diff --git a/0006-on.mouse_press b/0006-on.mouse_press
index b751dee..fe48806 100644
--- a/0006-on.mouse_press
+++ b/0006-on.mouse_press
@@ -29,11 +29,17 @@ on.mouse_press = function(x,y, mouse_button)
 	end
 	local button = on_button(x,y)
 	if button then
+		local n, id = new_comment(button.name, button.depth)
+		local parent = find_node(Global_state.thread, button.name)
+		assert(parent)
+		table.insert(parent.metadata.replies, id)
+		save_metadata(parent)
+		local item_index = find_comment_index(button.name)
 		table.insert(Global_state.thread.data,
-			button.item_index+1,
-			new_comment(button.name, button.depth))
+			item_index+1,
+			n)
 		A()
 	end
 	-- pan surface
 	Pan = {x=Viewport.x+x/Viewport.zoom,y=Viewport.y+y/Viewport.zoom}
-end
+end
\ No newline at end of file
diff --git a/0118-load_subtree b/0118-load_subtree
index 62fab08..ab21caa 100644
--- a/0118-load_subtree
+++ b/0118-load_subtree
@@ -1,7 +1,7 @@
-load_subtree = function(filename, out, depth)
+load_subtree = function(id, out, depth)
 	-- load a file and recursively all replies to it
---	print('load_subtree', filename)
-	local item = initialize_item(filename, depth)
+--	print('load_subtree', id)
+	local item = initialize_item(id, depth)
 	-- every item renders to a row consisting of two
 	-- columns: padding and 'item stuff'
 	local row = cols(Inter_comment_spacing)
@@ -12,9 +12,9 @@ load_subtree = function(filename, out, depth)
 	table.insert(row.data, item_stuff)
 	table.insert(item_stuff.data, item)
 	table.insert(item_stuff.data,
-		reply_button(filename, #out, depth))
+		reply_button(id, depth))
 	for i,reply_id in ipairs(item.metadata.replies) do
 		local reply = load_subtree(reply_id, out, depth+1)
 	end
 	return item
-end
\ No newline at end of file
+end
diff --git a/0120-initialize_item b/0120-initialize_item
index 2c7aae4..0c4e140 100644
--- a/0120-initialize_item
+++ b/0120-initialize_item
@@ -1,14 +1,14 @@
-initialize_item = function(filename, depth)
-	local result = {filename=full_path(filename)}
+initialize_item = function(id, depth)
+	local result = {
+		type='text',
+		id=id, filename=full_path(id),
+		width=Width, depth=depth,
+		metadata=load_metadata(id),
+		border=Border_color,
+	}
 	load_from_disk(result)
 	-- massage schema slightly; this isn't an editor state
 	result.data = result.lines
 	result.lines = nil
-	-- more fields
-	result.type = 'text'
-	result.width = Width
-	result.depth = depth
-	result.metadata = load_metadata(filename)
-	result.border = Border_color
 	return result
 end
\ No newline at end of file
diff --git a/0139-new_comment b/0139-new_comment
index 6d3b503..76b69d1 100644
--- a/0139-new_comment
+++ b/0139-new_comment
@@ -1,18 +1,23 @@
 new_comment = function(parent_id, depth)
+	local id = next_comment_id(parent_id)
+	print('creating', id)
 	local comment = {
 		type='text',
-		filename=full_path(next_comment(parent_id)),
+		id=id,
+		filename=full_path(id),
 		data={{data=''}},
 		width=Width,
 		depth=depth+1,
 		metadata={replies={}},
 		border=Border_color,
 	}
+	save_metadata(comment)
 	local result = cols(20)
 	table.insert(result.data, indent(depth+1))
 	local item_stuff = rows()
 	table.insert(result.data, item_stuff)
 	table.insert(item_stuff.data, comment)
-	table.insert(item_stuff.data, reply_button(comment.filename, 0, depth+1))
-	return result
-end
\ No newline at end of file
+	table.insert(item_stuff.data,
+		reply_button(comment.id, depth+1))
+	return result, id
+end
diff --git a/0142-reply_button b/0142-reply_button
index 4609681..c578c9d 100644
--- a/0142-reply_button
+++ b/0142-reply_button
@@ -1,10 +1,10 @@
-reply_button = function(filename, index, depth)
+reply_button = function(filename, depth)
 	return {
 		type='text', data={{data='reply'}},
 		button=true, margin=20,
-		name=filename, item_index=index,
+		name=filename,
 		depth=depth,
 		bg=Reply_button_color,
 		border=Reply_button_border_color,
 	}
-end
\ No newline at end of file
+end
diff --git a/0143-find_node b/0143-find_node
new file mode 100644
index 0000000..6c9d298
--- /dev/null
+++ b/0143-find_node
@@ -0,0 +1,15 @@
+find_node = function(node, id)
+	if node.type == 'text' and not node.button then
+		if node.id == id then
+			return node
+		else
+			return nil
+		end
+	end
+	if node.type == 'rows' or node.type == 'cols' then
+		for _,child in ipairs(node.data) do
+			local t = find_node(child, id)
+			if t then return t end
+		end
+	end
+end
diff --git a/0140-next_comment b/0144-next_comment_id
similarity index 80%
rename from 0140-next_comment
rename to 0144-next_comment_id
index 6c33a02..e52f29c 100644
--- a/0140-next_comment
+++ b/0144-next_comment_id
@@ -1,4 +1,4 @@
-next_comment = function(id)
+next_comment_id = function(id)
 	local num_replies = #load_metadata(id).replies
 	local corename = id:gsub('%.md$', '')
 	return ('%s-%d.md'):format(corename, num_replies)
diff --git a/0145-save_metadata b/0145-save_metadata
new file mode 100644
index 0000000..68c6671
--- /dev/null
+++ b/0145-save_metadata
@@ -0,0 +1,6 @@
+save_metadata = function(node)
+	--print('saving metadata for', node.id)
+	local mfile = metadata_file(node.id)
+	local mpath = save_dir_path(mfile)
+	love.filesystem.write(mpath, json.encode(node.metadata))
+end
diff --git a/0146-find_comment_index b/0146-find_comment_index
new file mode 100644
index 0000000..15aa19c
--- /dev/null
+++ b/0146-find_comment_index
@@ -0,0 +1,11 @@
+find_comment_index = function(id)
+	assert(Global_state.thread.type == 'rows')
+	for i,row in ipairs(Global_state.thread.data) do
+		assert(row.type == 'cols')
+		assert(#row.data == 2)
+		assert(row.data[2].type == 'rows')
+		if row.data[2].data[1].id == id then
+			return i
+		end
+	end
+end
\ No newline at end of file