diff --git a/classes/ComicPressStoryline.inc b/classes/ComicPressStoryline.inc
index 7a3c1b9..2c66dac 100644
--- a/classes/ComicPressStoryline.inc
+++ b/classes/ComicPressStoryline.inc
@@ -1,6 +1,7 @@
 <?php
 
 require_once('ComicPressDBInterface.inc');
+require_once('ComicPress.inc');
 
 class ComicPressStoryline {
 	var $_structure;
diff --git a/classes/ComicPressTagBuilder.inc b/classes/ComicPressTagBuilder.inc
index 855e145..f5208d9 100644
--- a/classes/ComicPressTagBuilder.inc
+++ b/classes/ComicPressTagBuilder.inc
@@ -42,6 +42,10 @@ class ComicPressTagBuilder {
 			case 'last':
 				$this->post = call_user_func(array($this->dbi, "get_${method}_post"), $this->storyline->build_from_restrictions($this->restrictions), $this->parent_post);
 				break;
+			case 'in':
+				if (!isset($arguments[0])) { throw new Exception('Need to specify a category');	}
+				$this->restrictions[] = array('child_of', $arguments[0]);
+				break;
 		}
 
 		return $this;
diff --git a/test/ComicPressTagBuilderTest.php b/test/ComicPressTagBuilderTest.php
index f0aa493..ccdaedc 100644
--- a/test/ComicPressTagBuilderTest.php
+++ b/test/ComicPressTagBuilderTest.php
@@ -10,12 +10,50 @@ class ComicPressTagBuilderTest extends PHPUnit_Framework_TestCase {
 		_reset_wp();
 	}
 
+	function testNewFactory() {
+		$core = new ComicPressTagBuilderFactory();
+	}
+
 	function providerTestBuilder() {
 		return array(
 			array(
-				array('next'),
+				array(
+					array('next')
+				),
 				array('get_next_post', array(1,2,3,4,5), 'current-post')
-			)
+			),
+			array(
+				array(
+					array('previous'),
+				),
+				array('get_previous_post', array(1,2,3,4,5), 'current-post')
+			),
+			array(
+				array(
+					array('first'),
+				),
+				array('get_first_post', array(1,2,3,4,5), 'current-post')
+			),
+			array(
+				array(
+					array('last'),
+				),
+				array('get_last_post', array(1,2,3,4,5), 'current-post')
+			),
+			array(
+				array(
+					array('in', 'category-1'),
+					array('last')
+				),
+				array('get_last_post', array(1), 'current-post')
+			),
+			array(
+				array(
+					array('in', 2),
+					array('first')
+				),
+				array('get_first_post', array(2,3,4), 'current-post')
+			),
 		);
 	}
 
@@ -23,7 +61,7 @@ class ComicPressTagBuilderTest extends PHPUnit_Framework_TestCase {
 	 * @dataProvider providerTestBuilder
 	 */
 	function testStorylineBuilder($instructions, $expected_dbi_call) {
-		global $post;
+		global $post, $wp_test_expectations;
 		$post = 'current-post';
 
 		$method = array_shift($expected_dbi_call);
@@ -38,17 +76,18 @@ class ComicPressTagBuilderTest extends PHPUnit_Framework_TestCase {
 		$storyline->set_flattened_storyline('0/1,0/2,0/2/3,0/2/4,0/5');
 
 		foreach (array(
-			array('cat_ID' => 1, 'cat_name' => 'Test 1', 'category_nicename' => 'category-1', 'category_parent' => 0),
-			array('cat_ID' => 2, 'cat_name' => 'Test 2', 'category_nicename' => 'category-2', 'category_parent' => 0),
-			array('cat_ID' => 3, 'cat_name' => 'Test 3', 'category_nicename' => 'category-3', 'category_parent' => 2),
-			array('cat_ID' => 4, 'cat_name' => 'Test 4', 'category_nicename' => 'category-4', 'category_parent' => 2),
-			array('cat_ID' => 5, 'cat_name' => 'Test 5', 'category_nicename' => 'category-5', 'category_parent' => 0),
-		) as $category) {
-			wp_insert_category($category);
+			1 => array('cat_name' => 'Test 1', 'category_nicename' => 'category-1', 'category_parent' => 0),
+			2 => array('cat_name' => 'Test 2', 'category_nicename' => 'category-2', 'category_parent' => 0),
+			3 => array('cat_name' => 'Test 3', 'category_nicename' => 'category-3', 'category_parent' => 2),
+			4 => array('cat_name' => 'Test 4', 'category_nicename' => 'category-4', 'category_parent' => 2),
+			5 => array('cat_name' => 'Test 5', 'category_nicename' => 'category-5', 'category_parent' => 0),
+		) as $id => $category) {
+			add_category($id, (object)$category);
 		}
 
 		foreach ($instructions as $instruction) {
-			$core = $core->{$instruction}();
+			$method = array_shift($instruction);
+			$core = call_user_func_array(array($core, $method), $instruction);
 		}
 	}
 }