diff --git a/wp-admin/includes/schema.php b/wp-admin/includes/schema.php
index 4ccc02fdb6..0115276dbd 100644
--- a/wp-admin/includes/schema.php
+++ b/wp-admin/includes/schema.php
@@ -482,7 +482,7 @@ function populate_options() {
 	'close_comments_days_old' => 14,
 	'thread_comments' => 1,
 	'thread_comments_depth' => 5,
-	'page_comments' => 0,
+	'page_comments' => 1,
 	'comments_per_page' => 50,
 	'default_comments_page' => 'newest',
 	'comment_order' => 'asc',
diff --git a/wp-admin/options-discussion.php b/wp-admin/options-discussion.php
index 4ba8be9830..525c83d1f4 100644
--- a/wp-admin/options-discussion.php
+++ b/wp-admin/options-discussion.php
@@ -98,17 +98,14 @@ printf( __('Enable threaded (nested) comments %s levels deep'), $thread_comments
 
 ?></label>
 <br />
-<label for="page_comments">
-<input name="page_comments" type="checkbox" id="page_comments" value="1" <?php checked('1', get_option('page_comments')); ?> />
 <?php
-
 $default_comments_page = '</label><label for="default_comments_page"><select name="default_comments_page" id="default_comments_page"><option value="newest"';
 if ( 'newest' == get_option('default_comments_page') ) $default_comments_page .= ' selected="selected"';
 $default_comments_page .= '>' . __('last') . '</option><option value="oldest"';
 if ( 'oldest' == get_option('default_comments_page') ) $default_comments_page .= ' selected="selected"';
 $default_comments_page .= '>' . __('first') . '</option></select>';
 
-printf( __('Break comments into pages with %1$s top level comments per page and the %2$s page displayed by default'), '</label><label for="comments_per_page"><input name="comments_per_page" type="number" step="1" min="0" id="comments_per_page" value="' . esc_attr(get_option('comments_per_page')) . '" class="small-text" />', $default_comments_page );
+printf( __('Break comments into pages with %1$s top level comments per page and the %2$s page displayed by default'), '<label for="comments_per_page"><input name="comments_per_page" type="number" step="1" min="0" id="comments_per_page" value="' . esc_attr(get_option('comments_per_page')) . '" class="small-text" />', $default_comments_page );
 
 ?></label>
 <br />
diff --git a/wp-admin/options.php b/wp-admin/options.php
index 6bad0fd61f..017725ddeb 100644
--- a/wp-admin/options.php
+++ b/wp-admin/options.php
@@ -83,7 +83,7 @@ if ( is_multisite() && ! is_super_admin() && 'update' != $action ) {
 
 $whitelist_options = array(
 	'general' => array( 'blogname', 'blogdescription', 'gmt_offset', 'date_format', 'time_format', 'start_of_week', 'timezone_string', 'WPLANG' ),
-	'discussion' => array( 'default_pingback_flag', 'default_ping_status', 'default_comment_status', 'comments_notify', 'moderation_notify', 'comment_moderation', 'require_name_email', 'comment_whitelist', 'comment_max_links', 'moderation_keys', 'blacklist_keys', 'show_avatars', 'avatar_rating', 'avatar_default', 'close_comments_for_old_posts', 'close_comments_days_old', 'thread_comments', 'thread_comments_depth', 'page_comments', 'comments_per_page', 'default_comments_page', 'comment_order', 'comment_registration' ),
+	'discussion' => array( 'default_pingback_flag', 'default_ping_status', 'default_comment_status', 'comments_notify', 'moderation_notify', 'comment_moderation', 'require_name_email', 'comment_whitelist', 'comment_max_links', 'moderation_keys', 'blacklist_keys', 'show_avatars', 'avatar_rating', 'avatar_default', 'close_comments_for_old_posts', 'close_comments_days_old', 'thread_comments', 'thread_comments_depth', 'comments_per_page', 'default_comments_page', 'comment_order', 'comment_registration' ),
 	'media' => array( 'thumbnail_size_w', 'thumbnail_size_h', 'thumbnail_crop', 'medium_size_w', 'medium_size_h', 'large_size_w', 'large_size_h', 'image_default_size', 'image_default_align', 'image_default_link_type' ),
 	'reading' => array( 'posts_per_page', 'posts_per_rss', 'rss_use_excerpt', 'show_on_front', 'page_on_front', 'page_for_posts', 'blog_public' ),
 	'writing' => array( 'default_category', 'default_email_category', 'default_link_category', 'default_post_format' )
diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index a88b3a8e22..52850b4017 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -321,7 +321,7 @@ function redirect_canonical( $requested_url = null, $do_redirect = true ) {
 				}
 			}
 
-			if ( get_option('page_comments') && ( ( 'newest' == get_option('default_comments_page') && get_query_var('cpage') > 0 ) || ( 'newest' != get_option('default_comments_page') && get_query_var('cpage') > 1 ) ) ) {
+			if ( ( 'newest' == get_option('default_comments_page') && get_query_var('cpage') > 0 ) || ( 'newest' != get_option('default_comments_page') && get_query_var('cpage') > 1 ) ) {
 				$addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit( $wp_rewrite->comments_pagination_base . '-' . get_query_var('cpage'), 'commentpaged' );
 				$redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] );
 			}
diff --git a/wp-includes/class-wp-comment-query.php b/wp-includes/class-wp-comment-query.php
index 2e978c4c72..4050e48182 100644
--- a/wp-includes/class-wp-comment-query.php
+++ b/wp-includes/class-wp-comment-query.php
@@ -865,6 +865,10 @@ class WP_Comment_Query {
 		$level = 0;
 		do {
 			$parent_ids = $levels[ $level ];
+			if ( ! $parent_ids ) {
+				break;
+			}
+
 			$where = 'WHERE ' . implode( ' AND ', $where_clauses ) . ' AND comment_parent IN (' . implode( ',', array_map( 'intval', $parent_ids ) ) . ')';
 			$comment_ids = $wpdb->get_col( "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']}" );
 
diff --git a/wp-includes/class-wp-comment.php b/wp-includes/class-wp-comment.php
index 955925b1b8..7225539d10 100644
--- a/wp-includes/class-wp-comment.php
+++ b/wp-includes/class-wp-comment.php
@@ -227,9 +227,11 @@ final class WP_Comment {
 	 * @since 4.4.0
 	 * @access public
 	 *
+	 * @param string $format Return value format. 'tree' for a hierarchical tree, 'flat' for a flattened array.
+	 *                       Default 'tree'.
 	 * @return array Array of `WP_Comment` objects.
 	 */
-	public function get_children() {
+	public function get_children( $format = 'tree' ) {
 		if ( is_null( $this->children ) ) {
 			$this->children = get_comments( array(
 				'parent' => $this->comment_ID,
@@ -237,7 +239,16 @@ final class WP_Comment {
 			) );
 		}
 
-		return $this->children;
+		if ( 'flat' === $format ) {
+			$children = array();
+			foreach ( $this->children as $child ) {
+				$children = array_merge( $children, array( $child ), $child->get_children( 'flat' ) );
+			}
+		} else {
+			$children = $this->children;
+		}
+
+		return $children;
 	}
 
 	/**
diff --git a/wp-includes/comment-functions.php b/wp-includes/comment-functions.php
index 949453e159..c58588e924 100644
--- a/wp-includes/comment-functions.php
+++ b/wp-includes/comment-functions.php
@@ -807,9 +807,6 @@ function get_comment_pages_count( $comments = null, $per_page = null, $threaded
 	if ( empty($comments) )
 		return 0;
 
-	if ( ! get_option( 'page_comments' ) )
-		return 1;
-
 	if ( !isset($per_page) )
 		$per_page = (int) get_query_var('comments_per_page');
 	if ( 0 === $per_page )
@@ -858,7 +855,7 @@ function get_page_of_comment( $comment_ID, $args = array() ) {
 	$defaults = array( 'type' => 'all', 'page' => '', 'per_page' => '', 'max_depth' => '' );
 	$args = wp_parse_args( $args, $defaults );
 
-	if ( '' === $args['per_page'] && get_option('page_comments') )
+	if ( '' === $args['per_page'] )
 		$args['per_page'] = get_query_var('comments_per_page');
 	if ( empty($args['per_page']) ) {
 		$args['per_page'] = 0;
diff --git a/wp-includes/comment-template.php b/wp-includes/comment-template.php
index d8c16a93da..b3ba1aea48 100644
--- a/wp-includes/comment-template.php
+++ b/wp-includes/comment-template.php
@@ -683,7 +683,7 @@ function get_comment_link( $comment = null, $args = array() ) {
 	$defaults = array( 'type' => 'all', 'page' => '', 'per_page' => '', 'max_depth' => '' );
 	$args = wp_parse_args( $args, $defaults );
 
-	if ( '' === $args['per_page'] && get_option('page_comments') )
+	if ( '' === $args['per_page'] )
 		$args['per_page'] = get_option('comments_per_page');
 
 	if ( empty($args['per_page']) ) {
@@ -1214,10 +1214,11 @@ function comments_template( $file = '/comments.php', $separate_comments = false
 	$comment_author_url = esc_url($commenter['comment_author_url']);
 
 	$comment_args = array(
-		'order'   => 'ASC',
 		'orderby' => 'comment_date_gmt',
 		'status'  => 'approve',
 		'post_id' => $post->ID,
+		'hierarchical' => 'threaded',
+		'no_found_rows' => false,
 		'update_comment_meta_cache' => false, // We lazy-load comment meta for performance.
 	);
 
@@ -1227,7 +1228,87 @@ function comments_template( $file = '/comments.php', $separate_comments = false
 		$comment_args['include_unapproved'] = array( $comment_author_email );
 	}
 
-	$comments = get_comments( $comment_args );
+	$per_page = (int) get_query_var( 'comments_per_page' );
+	if ( 0 === $per_page ) {
+		$per_page = (int) get_option( 'comments_per_page' );
+	}
+
+	$flip_comment_order = $trim_comments_on_page = false;
+	if ( $post->comment_count > $per_page ) {
+		$comment_args['number'] = $per_page;
+
+		/*
+		 * For legacy reasons, higher page numbers always mean more recent comments, regardless of sort order.
+		 * Since we don't have full pagination info until after the query, we use some tricks to get the
+		 * right comments for the current page.
+		 *
+		 * Abandon all hope, ye who enter here!
+		 */
+		$page = (int) get_query_var( 'cpage' );
+		if ( 'newest' === get_option( 'default_comments_page' ) ) {
+			if ( $page ) {
+				$comment_args['order'] = 'ASC';
+
+				/*
+				 * We don't have enough data (namely, the total number of comments) to calculate an
+				 * exact offset. We'll fetch too many comments, and trim them as needed
+				 * after the query.
+				 */
+				$offset = ( $page - 2 ) * $per_page;
+				if ( 0 > $offset ) {
+					// `WP_Comment_Query` doesn't support negative offsets.
+					$comment_args['offset'] = 0;
+				} else {
+					$comment_args['offset'] = $offset;
+				}
+
+				// Fetch double the number of comments we need.
+				$comment_args['number'] += $per_page;
+				$trim_comments_on_page = true;
+			} else {
+				$comment_args['order'] = 'DESC';
+				$comment_args['offset'] = 0;
+				$flip_comment_order = true;
+			}
+		} else {
+			$comment_args['order'] = 'ASC';
+			if ( $page ) {
+				$comment_args['offset'] = ( $page - 1 ) * $per_page;
+			} else {
+				$comment_args['offset'] = 0;
+			}
+		}
+	}
+
+	$comment_query = new WP_Comment_Query( $comment_args );
+	$_comments = $comment_query->comments;
+
+	// Delightful pagination quirk #1: first page of results sometimes needs reordering.
+	if ( $flip_comment_order ) {
+		$_comments = array_reverse( $_comments );
+	}
+
+	// Delightful pagination quirk #2: reverse chronological order requires page shifting.
+	if ( $trim_comments_on_page ) {
+		// Correct the value of max_num_pages, which is wrong because we manipulated the per_page 'number'.
+		$comment_query->max_num_pages = ceil( $comment_query->found_comments / $per_page );
+
+		// Identify the number of comments that should appear on page 1.
+		$page_1_count = $comment_query->found_comments - ( ( $comment_query->max_num_pages - 1 ) * $per_page );
+
+		// Use that value to shift the matched comments.
+		if ( 1 === $page ) {
+			$_comments = array_slice( $_comments, 0, $page_1_count );
+		} else {
+			$_comments = array_slice( $_comments, $page_1_count, $per_page );
+		}
+	}
+
+	// Trees must be flattened before they're passed to the walker.
+	$comments_flat = array();
+	foreach ( $_comments as $_comment ) {
+		$comments_flat = array_merge( $comments_flat, array( $_comment ), $_comment->get_children( 'flat' ) );
+	}
 
 	/**
 	 * Filter the comments array.
@@ -1237,9 +1318,10 @@ function comments_template( $file = '/comments.php', $separate_comments = false
 	 * @param array $comments Array of comments supplied to the comments template.
 	 * @param int   $post_ID  Post ID.
 	 */
-	$wp_query->comments = apply_filters( 'comments_array', $comments, $post->ID );
+	$wp_query->comments = apply_filters( 'comments_array', $comments_flat, $post->ID );
 	$comments = &$wp_query->comments;
 	$wp_query->comment_count = count($wp_query->comments);
+	$wp_query->max_num_comment_pages = $comment_query->max_num_pages;
 
 	if ( $separate_comments ) {
 		$wp_query->comments_by_type = separate_comments($comments);
@@ -1249,7 +1331,7 @@ function comments_template( $file = '/comments.php', $separate_comments = false
 	}
 
 	$overridden_cpage = false;
-	if ( '' == get_query_var('cpage') && get_option('page_comments') ) {
+	if ( '' == get_query_var('cpage') ) {
 		set_query_var( 'cpage', 'newest' == get_option('default_comments_page') ? get_comment_pages_count() : 1 );
 		$overridden_cpage = true;
 	}
@@ -1825,9 +1907,14 @@ function wp_list_comments( $args = array(), $comments = null ) {
 		} else {
 			$_comments = $wp_query->comments;
 		}
+
+		// Pagination is already handled by `WP_Comment_Query`, so we tell Walker not to bother.
+		if ( 1 < $wp_query->max_num_comment_pages ) {
+			$r['page'] = 1;
+		}
 	}
 
-	if ( '' === $r['per_page'] && get_option('page_comments') )
+	if ( '' === $r['per_page'] )
 		$r['per_page'] = get_query_var('comments_per_page');
 
 	if ( empty($r['per_page']) ) {
@@ -1866,7 +1953,6 @@ function wp_list_comments( $args = array(), $comments = null ) {
 	}
 
 	$output = $walker->paged_walk( $_comments, $r['max_depth'], $r['page'], $r['per_page'], $r );
-	$wp_query->max_num_comment_pages = $walker->max_pages;
 
 	$in_comment_loop = false;
 
diff --git a/wp-includes/default-filters.php b/wp-includes/default-filters.php
index 20684e220f..c50a9d949c 100644
--- a/wp-includes/default-filters.php
+++ b/wp-includes/default-filters.php
@@ -316,6 +316,9 @@ add_filter( 'default_option_link_manager_enabled', '__return_true' );
 // This option no longer exists; tell plugins we always support auto-embedding.
 add_filter( 'default_option_embed_autourls', '__return_true' );
 
+// This option no longer exists; tell plugins we want comment pagination.
+add_filter( 'pre_option_page_comments', '__return_true' );
+
 // Default settings for heartbeat
 add_filter( 'heartbeat_settings', 'wp_heartbeat_settings' );
 
diff --git a/wp-includes/link-template.php b/wp-includes/link-template.php
index 7538a52aff..4861478d0f 100644
--- a/wp-includes/link-template.php
+++ b/wp-includes/link-template.php
@@ -2590,7 +2590,7 @@ function get_comments_pagenum_link( $pagenum = 1, $max_page = 0 ) {
 function get_next_comments_link( $label = '', $max_page = 0 ) {
 	global $wp_query;
 
-	if ( !is_singular() || !get_option('page_comments') )
+	if ( ! is_singular() )
 		return;
 
 	$page = get_query_var('cpage');
@@ -2644,7 +2644,7 @@ function next_comments_link( $label = '', $max_page = 0 ) {
  * @return string|void HTML-formatted link for the previous page of comments.
  */
 function get_previous_comments_link( $label = '' ) {
-	if ( !is_singular() || !get_option('page_comments') )
+	if ( ! is_singular() )
 		return;
 
 	$page = get_query_var('cpage');
@@ -2692,7 +2692,7 @@ function previous_comments_link( $label = '' ) {
 function paginate_comments_links($args = array()) {
 	global $wp_rewrite;
 
-	if ( !is_singular() || !get_option('page_comments') )
+	if ( ! is_singular() )
 		return;
 
 	$page = get_query_var('cpage');
@@ -2737,7 +2737,7 @@ function get_the_comments_navigation( $args = array() ) {
 	$navigation = '';
 
 	// Are there comments to navigate through?
-	if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) {
+	if ( get_comment_pages_count() > 1 ) {
 		$args = wp_parse_args( $args, array(
 			'prev_text'          => __( 'Older comments' ),
 			'next_text'          => __( 'Newer comments' ),
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 84e2687f80..e4b5b979dd 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34560';
+$wp_version = '4.4-alpha-34561';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.