diff --git a/includes/object.entity_controller.inc b/includes/object.entity_controller.inc
index 9464d7b5..87b5e4de 100644
--- a/includes/object.entity_controller.inc
+++ b/includes/object.entity_controller.inc
@@ -30,6 +30,7 @@ class IslandoraObjectEntityController implements DrupalEntityControllerInterface
    */
   public function load($ids = array(), $conditions = array()) {
     if (!empty($conditions)) {
+      // TODO: Allow loading by specifying IDs in the condition.
       throw new Exception('Conditions not implemented.');
     }
 
diff --git a/includes/tuque_wrapper.inc b/includes/tuque_wrapper.inc
index 2f4ea1df..d14a86b3 100644
--- a/includes/tuque_wrapper.inc
+++ b/includes/tuque_wrapper.inc
@@ -115,10 +115,6 @@ class IslandoraFedoraRepository extends FedoraRepository {
       foreach ($object as $dsid => $datastream) {
         islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_INGESTED_HOOK, $object->models, $dsid, $object, $datastream);
       }
-      // Fire of event if rules is enabled.
-      if (module_exists('rules')) {
-        rules_invoke_event('islandora_object_ingested', $object);
-      }
       return $ret;
     }
     catch (Exception $e) {
diff --git a/includes/utilities.inc b/includes/utilities.inc
index 26633df5..7476948b 100644
--- a/includes/utilities.inc
+++ b/includes/utilities.inc
@@ -188,12 +188,18 @@ function islandora_describe_repository($url = NULL) {
  */
 function islandora_invoke_hook_list($hook, array $refinements, array $args) {
   $return = array();
-  foreach (islandora_build_hook_list($hook, $refinements) as $hook) {
-    array_unshift($args, $hook);
+  foreach (islandora_build_hook_list($hook, $refinements) as $refined_hook) {
+    array_unshift($args, $refined_hook);
     $result = call_user_func_array('module_invoke_all', $args);
     $return = array_merge_recursive($return, $result);
     array_shift($args);
   }
+  if (module_exists('rules') && $event = rules_get_cache("event_$hook")) {
+    $parameters = $event->parameterInfo();
+    $rule_args = array_slice($args, 0, count($parameters));
+    array_unshift($rule_args, $hook);
+    $result = call_user_func_array('rules_invoke_event', $rule_args);
+  }
   return $return;
 }
 
diff --git a/islandora.module b/islandora.module
index 603ab6a0..ac63069c 100644
--- a/islandora.module
+++ b/islandora.module
@@ -1543,21 +1543,25 @@ function islandora_entity_property_info() {
     'type' => 'text',
     'label' => t('Object Label'),
     'description' => t('The label of the object.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
   $object_properties['owner'] = array(
     'type' => 'text',
     'label' => t('Object Owner'),
     'description' => t('The name of the owner of the object.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
   $object_properties['state'] = array(
     'type' => 'text',
     'label' => t('Object State'),
     'description' => t('An initial representing the state of the object.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
   $object_properties['models'] = array(
     'type' => 'list<text>',
     'label' => t('Content Models'),
     'description' => t('The list of content models which the object has.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
   $object_properties['createdDate'] = array(
     'type' => 'text',
@@ -1570,15 +1574,34 @@ function islandora_entity_property_info() {
     'label' => t('ID'),
     'description' => t('The identifier of the datastream.'),
   );
+  $datastream_properties['state'] = array(
+    'type' => 'text',
+    'label' => t('Datastream State'),
+    'description' => t('An initial representing the state of the datastream.'),
+    'setter callback' => 'islandora_entity_set_property',
+  );
   $datastream_properties['label'] = array(
     'type' => 'text',
     'label' => t('Datastream Label'),
     'description' => t('The label of the datastream.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
   $datastream_properties['mimetype'] = array(
     'type' => 'text',
     'label' => t('MIME type'),
     'description' => t('Content type of the datastream.'),
+    'setter callback' => 'islandora_entity_set_property',
+  );
+  $datastream_properties['parent'] = array(
+    'type' => 'islandora_object',
+    'label' => t('Object'),
+    'description' => t('The Tuque object on which this datastream exists.'),
+  );
+  $datastream_properties['content'] = array(
+    'type' => 'text',
+    'label' => t('Datastream content'),
+    'description' => t('The contents of the datastream; only useful when the content is textual.'),
+    'setter callback' => 'islandora_entity_set_property',
   );
 
   return $info;
@@ -2001,3 +2024,15 @@ function islandora_islandora_object_alter(AbstractObject $object, array &$contex
     islandora_set_defer_derivatives_flag($object);
   }
 }
+
+/**
+ * Set property on an entity.
+ *
+ * Drupal's usual entity_property_verbatim_set() does not work, as tries to use
+ * ArrayAccess stuff instead of setting properties directly.
+ */
+function islandora_entity_set_property(&$data, $name, $value, $langcode) {
+  if (is_object($data)) {
+    $data->$name = $value;
+  }
+}
diff --git a/islandora.rules.inc b/islandora.rules.inc
index 02f5c822..2562656a 100644
--- a/islandora.rules.inc
+++ b/islandora.rules.inc
@@ -21,6 +21,76 @@ function islandora_rules_event_info() {
         ),
       ),
     ),
+    'islandora_datastream_ingested' => array(
+      'group' => t('Islandora'),
+      'label' => t('Datastream ingested'),
+      'variables' => array(
+        'object' => array(
+          'type' => 'islandora_object',
+          'label' => t('The ingested object'),
+          'description' => t('A Tuque object for the Fedora object on which the datastream exists, as an entity.'),
+        ),
+        'datastream' => array(
+          'type' => 'islandora_datastream',
+          'label' => t('Datastream ID'),
+          'description' => t('The ID of the ingested datastream.'),
+        ),
+      ),
+    ),
+    'islandora_object_modified' => array(
+      'group' => t('Islandora'),
+      'label' => t('Object modified'),
+      'variables' => array(
+        'object' => array(
+          'type' => 'islandora_object',
+          'label' => t('The modified object'),
+          'description' => t('A Tuque object for the modified Fedora object, as an entity.'),
+        ),
+      ),
+    ),
+    'islandora_datastream_modified' => array(
+      'group' => t('Islandora'),
+      'label' => t('Datastream modified'),
+      'variables' => array(
+        'object' => array(
+          'type' => 'islandora_object',
+          'label' => t('The modified object'),
+          'description' => t('A Tuque object for the Fedora object on which the datastream exists, as an entity.'),
+        ),
+        'datastream' => array(
+          'type' => 'islandora_datastream',
+          'label' => t('Datastream'),
+          'description' => t('The modified datastream.'),
+        ),
+      ),
+    ),
+    'islandora_object_purged' => array(
+      'group' => t('Islandora'),
+      'label' => t('Object purged'),
+      'variables' => array(
+        'object' => array(
+          'type' => 'text',
+          'label' => t('Object ID'),
+          'description' => t('The ID of the purged object.'),
+        ),
+      ),
+    ),
+    'islandora_datastream_purged' => array(
+      'group' => t('Islandora'),
+      'label' => t('Datastream purged'),
+      'variables' => array(
+        'object' => array(
+          'type' => 'islandora_object',
+          'label' => t('Object'),
+          'description' => t('A Tuque object for the Fedora object on which the datastream existed, as an entity.'),
+        ),
+        'datastream' => array(
+          'type' => 'text',
+          'label' => t('Datastream ID'),
+          'description' => t('The identifier of the purged datastream.'),
+        ),
+      ),
+    ),
   );
 }
 
@@ -60,6 +130,35 @@ function islandora_rules_relationship_parameter_array() {
   );
 }
 
+/**
+ * Helper function; get default parameters for the XPath condition and action.
+ */
+function islandora_rules_base_xpath_parameters() {
+  return array(
+    'object' => array(
+      'type' => 'islandora_object',
+      'label' => t('Object'),
+      'description' => t('The object containing the datastream to check.'),
+    ),
+    'datastream_id' => array(
+      'type' => 'text',
+      'label' => t('Datastream'),
+      'description' => t('The identifier of the XML datastream to check.'),
+    ),
+    'xpath' => array(
+      'type' => 'text',
+      'label' => t('XPath'),
+      'description' => t('An XPath to evaluate.'),
+    ),
+    'xpath_namespaces' => array(
+      'type' => 'taxonomy_vocabulary',
+      'label' => t('XPath Namespace Taxonomy'),
+      'description' => t('A flat taxonomy of which the terms are namespace prefixes and the description contains the URI for the namespace.'),
+    ),
+  );
+}
+
+
 /**
  * Implements hook_rules_condition_info().
  */
@@ -71,6 +170,27 @@ function islandora_rules_condition_info() {
     'group' => t('Islandora'),
     'parameter' => islandora_rules_relationship_parameter_array(),
   );
+  $cond['islandora_object_has_datastream'] = array(
+    'label' => t('Check object for existence of a datastream'),
+    'group' => t('Islandora'),
+    'parameter' => array(
+      'object' => array(
+        'type' => 'islandora_object',
+        'label' => t('Object'),
+        'description' => t('The object containing the datastream to check.'),
+      ),
+      'datastream_id' => array(
+        'type' => 'text',
+        'label' => t('Datastream'),
+        'description' => t('The identifier of the datastream to check.'),
+      ),
+    ),
+  );
+  $cond['islandora_rules_datastream_has_xpath'] = array(
+    'label' => t('Check for an XPath match in an XML datastream'),
+    'group' => t('Islandora'),
+    'parameter' => islandora_rules_base_xpath_parameters(),
+  );
 
   return $cond;
 }
@@ -92,8 +212,132 @@ function islandora_rules_action_info() {
     'group' => t('Islandora'),
     'parameter' => islandora_rules_relationship_parameter_array(),
   );
+
+  $cond['islandora_rules_datastream_load'] = array(
+    'label' => t('Load a datastream from an object.'),
+    'group' => t('Islandora'),
+    'parameter' => array(
+      'object' => array(
+        'type' => 'islandora_object',
+        'label' => t('Object'),
+        'description' => t('A Tuque object for the Fedora object from which to load the datastream, as an entity.'),
+      ),
+      'datastream_id' => array(
+        'type' => 'text',
+        'label' => t('Datastream ID'),
+        'description' => t('A string containing the identity of the datastream to load from the object.'),
+      ),
+    ),
+    'provides' => array(
+      'datastream' => array(
+        'type' => 'islandora_datastream',
+        'label' => t('Loaded datastream instance'),
+      ),
+    ),
+  );
+  $cond['islandora_rules_datastream_load_domxpath'] = array(
+    'label' => t('Load a DOMXPath for a given XML.'),
+    'group' => t('Islandora DOMXPath'),
+    'parameter' => array(
+      'datastream' => array(
+        'type' => 'text',
+        'label' => t('XML'),
+        'description' => t('A string containing the XML to load.'),
+      ),
+    ),
+    'provides' => array(
+      'islandora_domxpath' => array(
+        'type' => 'islandora_domxpath',
+        'label' => t('Loaded DOMXPath instance'),
+      ),
+    ),
+  );
+  $cond['islandora_rules_datastream_load_xpath'] = array(
+    'label' => t('Load a DOMXPath from a datastream.'),
+    'group' => t('Islandora DOMXPath'),
+    'parameter' => array(
+      'datastream' => array(
+        'type' => 'islandora_datastream',
+        'label' => t('Datastream'),
+        'description' => t('A datastream containing the XML to load.'),
+      ),
+    ),
+    'provides' => array(
+      'islandora_domxpath' => array(
+        'type' => 'islandora_domxpath',
+        'label' => t('Loaded DOMXPath instance'),
+      ),
+    ),
+  );
+  $cond['islandora_rules_datastream_load_namespace_vocab'] = array(
+    'label' => t('Register namespaces on a DOMXPath instance.'),
+    'group' => t('Islandora DOMXPath'),
+    'parameter' => array(
+      'value' => array(
+        'type' => 'islandora_domxpath',
+        'label' => t('DOMXPath instance'),
+        'description' => t('The DOMXPath instance on which to register the namespaces.'),
+      ),
+      'xpath_namespaces' => array(
+        'type' => 'taxonomy_vocabulary',
+        'label' => t('XPath Namespace Taxonomy'),
+        'description' => t('A flat taxonomy of which the terms are namespace prefixes and the description contains the URI for the namespace.'),
+      ),
+    ),
+  );
+  $cond['islandora_rules_datastream_query_xpath'] = array(
+    'label' => t('Query nodes from DOMXPath instance.'),
+    'group' => t('Islandora DOMXPath'),
+    'parameter' => array(
+      'xpath' => array(
+        'type' => 'islandora_domxpath',
+        'label' => t('DOMXPath instance'),
+        'description' => t('The DOMXPath instance on which to perform the query.'),
+      ),
+      'query' => array(
+        'type' => 'text',
+        'label' => t('XPath query'),
+        'description' => t('The XPath query to perform.'),
+      ),
+      'context_node' => array(
+        'type' => 'islandora_domnode',
+        'label' => t('Context Node'),
+        'description' => t('If provided, the query will be performed relative to the provided node.'),
+        'optional' => TRUE,
+        'default value' => NULL,
+        'allow null' => TRUE,
+      ),
+    ),
+    'provides' => array(
+      'nodes' => array(
+        'type' => 'list<islandora_domnode>',
+        'label' => t('Queried DOMNode elements'),
+      ),
+    ),
+  );
+
+  $cond['islandora_rules_datastream_set_xpath'] = array(
+    'label' => t('Set value in elements matched by an XPath in an XML datastream'),
+    'group' => t('Islandora'),
+    'parameter' => islandora_rules_base_xpath_parameters() + array(
+      'value' => array(
+        'type' => 'text',
+        'label' => t('Value'),
+        'description' => t('The value to set in the XML on elements matched by the XPath.'),
+      ),
+    ),
+  );
+
   return $cond;
 }
+
+/**
+ * Rules action callback; grab a datastream from an object.
+ */
+function islandora_rules_datastream_load(AbstractObject $object, $datastream_id) {
+  return array('datastream' => $object[$datastream_id]);
+}
+
 /**
  * Checks that there is a relationship match on the given object.
  *
@@ -133,3 +377,202 @@ function islandora_object_remove_relationship($sub, $pred_uri, $pred, $object, $
 function islandora_object_add_relationship($sub, $pred_uri, $pred, $object, $type) {
   $sub->relationships->add($pred_uri, $pred, $object, $type);
 }
+
+/**
+ * Rules Action callback; instantiate a DOMXPath with some XML.
+ */
+function islandora_rules_datastream_load_domxpath($string) {
+  $doc = new DOMDocument();
+  $doc->loadXML($string);
+  $xpath = new DOMXPath($doc);
+  return array('islandora_domxpath' => $xpath);
+}
+
+/**
+ * Rules Action callback; load namespaces onto a DOMXPath instance.
+ *
+ * @param DOMXPath $xpath
+ *   A DOMXPath instance.
+ * @param object $xpath_vocab
+ *   A loaded Drupal taxonomy vocabulary object, in which terms are understood
+ *   to be namespace prefixes and descriptions are the namespace URIs.
+ */
+function islandora_rules_datastream_load_namespace_vocab($xpath, $xpath_vocab) {
+  foreach (taxonomy_get_tree($xpath_vocab->vid, 0, 1, FALSE) as $term) {
+    $xpath->registerNamespace($term->name, $term->description);
+  }
+}
+
+/**
+ * Rules XPath helper; grab the datastream content and build a DOMXPath.
+ */
+function islandora_rules_datastream_load_xpath(AbstractDatastream $datastream, $xpath_vocab) {
+  $result = islandora_rules_datastream_load_domxpath($datastream->content, $xpath_vocab);
+  islandora_rules_datastream_load_namespace_vocab($result['islandora_domxpath'], $xpath_vocab);
+  return $result;
+}
+
+/**
+ * Rules Condition callback; test that an XPath returns a non-empty result set.
+ */
+function islandora_rules_datastream_has_xpath(AbstractObject $object, $datastream_id, $search_xpath, $xpath_vocab) {
+  $datastream = $object[$datastream_id];
+  $xpath = islandora_rules_datastream_load_xpath($datastream, $xpath_vocab);
+  $result = $xpath['islandora_domxpath']->query($search_xpath);
+  return $result->length > 0;
+}
+
+/**
+ * Rules Action callback; set the value of all matched nodes.
+ */
+function islandora_rules_datastream_set_xpath(AbstractObject $object, $datastream_id, $search_xpath, $xpath_vocab, $value) {
+  $datastream = $object[$datastream_id];
+  $xpath = islandora_rules_datastream_load_xpath($datastream, $xpath_vocab);
+  $result = $xpath['islandora_domxpath']->query($search_xpath);
+  foreach ($result as $node) {
+    $node->nodeValue = $value;
+  }
+  $datastream->content = $xpath['islandora_domxpath']->document->saveXML();
+}
+
+/**
+ * Implements hook_rules_data_info().
+ */
+function islandora_rules_data_info() {
+  return array(
+    'islandora_domxpath' => array(
+      'label' => t('DOMXPath instance'),
+      'group' => t('Islandora'),
+      'property info' => array(
+        'content' => array(
+          'type' => 'text',
+          'label' => t('XML Content'),
+          'computed' => TRUE,
+          'getter callback' => 'islandora_rules_get_domxpath_document_content',
+          'token type' => 'string',
+        ),
+      ),
+      'wrap' => TRUE,
+    ),
+    'islandora_domnode' => array(
+      'label' => t('DOMNode instance'),
+      'group' => t('Islandora'),
+      'property info' => array(
+        'node_value' => array(
+          'type' => 'text',
+          'label' => t('Node value'),
+          'computed' => TRUE,
+          'getter callback' => 'islandora_rules_property_get',
+          'setter callback' => 'islandora_rules_property_set',
+          'property' => 'nodeValue',
+          'token type' => 'string',
+        ),
+        'text_content' => array(
+          'type' => 'text',
+          'label' => t('Text content'),
+          'computed' => TRUE,
+          'getter callback' => 'islandora_rules_property_get',
+          'property' => 'textContent',
+          'token type' => 'string',
+        ),
+      ),
+      'wrap' => TRUE,
+    ),
+    'islandora_domelement' => array(
+      'label' => t('DOMElement instance'),
+      'group' => t('Islandora'),
+      'parent' => 'islandora_domnode',
+      'wrap' => TRUE,
+    ),
+  );
+}
+
+/**
+ * Property setter helper; set a property on an object.
+ *
+ * In Rules, properties can contain lowercase and numeric characters. Since
+ * we want to refer to "nodeValue", we have to step around the Rules constraint.
+ *
+ * @param object $data
+ *   The object on which to set the property, described by $info['property'].
+ * @param array $options
+ *   An array of options... Not sure how it's used? Not touched by us, in any
+ *   case. :P
+ * @param string $name
+ *   The name of the property to set, as used by Rules.
+ * @param string $type
+ *   The type of object on which the property is being set, as used by Rules.
+ * @param array $info
+ *   An associative array describing this property. In addition to that
+ *   required by Rules/the Entity API, should contain:
+ *   - property: A string indicate the actual property on the $data we wish to
+ *     set.
+ */
+function islandora_rules_property_get($data, array $options, $name, $type, $info) {
+  return $data->$info['property'];
+}
+
+/**
+ * Property setter helper; set a property on an object.
+ *
+ * In Rules, properties can contain lowercase and numeric characters. Since
+ * we want to refer to "nodeValue", we have to step around the Rules constraint.
+ *
+ * @param object $data
+ *   The object on which to set the property, described by $info['property'].
+ * @param string $name
+ *   The name of the property to set, as used by Rules.
+ * @param mixed $value
+ *   The value to set on the property.
+ * @param string $langcode
+ *   A string indicating the language being set, or NULL.
+ * @param string $type
+ *   The type of object on which the property is being set, as used by Rules.
+ * @param array $info
+ *   An associative array describing this property. In addition to that
+ *   required by Rules/the Entity API, should contain:
+ *   - property: A string indicate the actual property on the $data we wish to
+ *     set.
+ */
+function islandora_rules_property_set(&$data, $name, $value, $langcode, $type, $info) {
+  $data->$info['property'] = $value;
+}
+
+/**
+ * Rules property "get" callback; get XML contained in a DOMXPath instance.
+ *
+ * @param DOMXPath $xpath
+ *   A DOMXPath instance.
+ *
+ * @return string
+ *   The XML contained inside of the DOMXPath instance.
+ */
+function islandora_rules_get_domxpath_document_content(DOMXPath $xpath) {
+  return $xpath->document->saveXML();
+}
+
+/**
+ * Rules action callback; perform a query on a DOMXPath instance.
+ *
+ * @param DOMXPath $xpath
+ *   A DOMXPath instance.
+ * @param string $query
+ *   An XPath query.
+ * @param DOMNode $context_node
+ *   An optional DOMNode. If provided, the query will be performed relative to
+ *   the given node.
+ *
+ * @return array
+ *   An array containing:
+ *   - nodes: An array containing the results of the query.
+ */
+function islandora_rules_datastream_query_xpath(DOMXPath $xpath, $query, DOMNode $context_node = NULL) {
+  return array('nodes' => iterator_to_array($xpath->query($query, $context_node)));
+}
+
+/**
+ * Rules condition callback; check for the datastream on an object.
+ */
+function islandora_object_has_datastream(AbstractObject $object, $datastream_id) {
+  return isset($object[$datastream_id]);
+}