diff --git a/db/sqlite.py b/db/sqlite.py
index 7bbba3a..586493e 100644
--- a/db/sqlite.py
+++ b/db/sqlite.py
@@ -6,13 +6,13 @@ class DB:
         pass
 
     def get_subforums(self):
-        return self._db().execute('select forum_id, name, description from subforums').fetchall()
+        return self._db().execute('select forum_id, name, description from subforums')
 
     def get_subforum(self, subforum):
         return self._db().execute('select name, description from subforums where forum_id = ?', (subforum,)).fetchone()
 
     def get_threads(self, subforum):
-        return self._db().execute('select thread_id, title from threads where forum_id = ?', (subforum,)).fetchall()
+        return self._db().execute('select thread_id, title from threads where forum_id = ?', (subforum,))
 
     def get_thread(self, thread):
         db = self._db()
@@ -29,7 +29,7 @@ class DB:
             where thread_id = ? and author_id = user_id
             ''',
             (thread,)
-        ).fetchall()
+        )
         return title, text, author, author_id, comments
 
     def get_thread_title(self, thread_id):
@@ -48,15 +48,30 @@ class DB:
             where thread_id = ?
             ''',
             (thread,)
-        ).fetchall()
+        )
 
-    def get_comment_tree(self, comment):
+    def get_subcomments(self, comment_id):
         db = self._db()
-        parent = db.execute('select text from comments where comment_id = ?', (comment,)).fetchall()
-        children = db.execute('select text from comments where parent_id = ?', (comment,)).fetchall()
-        print(parent, children)
-        return str(parent) + str(children)
-        return parent
+        thread_id, parent_id, title = db.execute('''
+            select threads.thread_id, parent_id, title
+            from threads, comments
+            where comment_id = ? and threads.thread_id = comments.thread_id
+            ''',
+            (comment_id,)
+        ).fetchone()
+        # Recursive CTE, see https://www.sqlite.org/lang_with.html
+        return thread_id, parent_id, title, db.execute('''
+            with recursive
+              descendant_of(id) as (
+                select comment_id from comments where comment_id = ?
+                union
+                select comment_id from descendant_of, comments where id = parent_id
+              )
+            select id, parent_id, name, text from descendant_of, comments, users
+            where id = comment_id and user_id = author_id
+            ''',
+            (comment_id,)
+        )
 
     def get_user_password(self, username):
         return self._db().execute('''
@@ -127,5 +142,37 @@ class DB:
         )
         db.commit()
 
+    def add_comment_to_thread(self, thread_id, author_id, text, time):
+        db = self._db()
+        c = db.cursor()
+        c.execute('''
+            insert into comments(thread_id, author_id, text, create_time, modify_time)
+            select ?, ?, ?, ?, ?
+            from threads
+            where thread_id = ?
+            ''',
+            (thread_id, author_id, text, time, time, thread_id)
+        )
+        rowid = c.lastrowid
+        db.commit()
+        return rowid is not None
+
+    def add_comment_to_comment(self, parent_id, author_id, text, time):
+        db = self._db()
+        c = db.cursor()
+        print(c.lastrowid, parent_id)
+        c.execute('''
+            insert into comments(thread_id, parent_id, author_id, text, create_time, modify_time)
+            select thread_id, ?, ?, ?, ?, ?
+            from comments
+            where comment_id = ?
+            ''',
+            (parent_id, author_id, text, time, time, parent_id)
+        )
+        print(c.lastrowid)
+        rowid = c.lastrowid
+        db.commit()
+        return rowid is not None
+
     def _db(self):
         return sqlite3.connect(self.conn)
diff --git a/main.py b/main.py
index 477b640..9532faa 100644
--- a/main.py
+++ b/main.py
@@ -43,8 +43,16 @@ def thread(thread_id):
 
 @app.route('/comment/<int:comment_id>/')
 def comment(comment_id):
-    #return str(db.get_comment_tree(comment_id)[0])
-    return str(db.get_comment_tree(comment_id))
+    user_id = session.get('user_id')
+    thread_id, parent_id, title, comments = db.get_subcomments(comment_id)
+    comments = create_comment_tree(comments)
+    return render_template(
+        'comments.html',
+        title = title,
+        comments = comments,
+        parent_id = parent_id,
+        thread_id = thread_id,
+    )
 
 @app.route('/login/', methods = ['GET', 'POST'])
 def login():
@@ -129,21 +137,50 @@ def delete_thread(thread_id):
     flash('Thread has been deleted', 'success')
     return redirect(url_for('index'))
 
+@app.route('/thread/<int:thread_id>/comment/', methods = ['POST'])
+def add_comment(thread_id):
+    user_id = session.get('user_id')
+    if user_id is None:
+        return redirect(url_for('login'))
+
+    if db.add_comment_to_thread(thread_id, user_id, request.form['text'], time.time_ns()):
+        flash('Added comment', 'success')
+    else:
+        flash('Failed to add comment', 'error')
+    return redirect(url_for('thread', thread_id = thread_id))
+
+@app.route('/comment/<int:comment_id>/comment/', methods = ['POST'])
+def add_comment_parent(comment_id):
+    user_id = session.get('user_id')
+    if user_id is None:
+        return redirect(url_for('login'))
+
+    if db.add_comment_to_comment(comment_id, user_id, request.form['text'], time.time_ns()):
+        flash('Added comment', 'success')
+    else:
+        flash('Failed to add comment', 'error')
+    return redirect(url_for('comment', comment_id = comment_id))
+
+
 class Comment:
-    def __init__(self, author, text):
+    def __init__(self, id, author, text):
+        self.id = id
         self.author = author
         self.text = text
         self.children = []
 
 def create_comment_tree(comments):
+    # Collect comments first, then build the tree in case we encounter a child before a parent
+    comment_map = {
+        comment_id: (Comment(comment_id, author, text), parent_id)
+        for comment_id, parent_id, author, text
+        in comments
+    }
     root = []
-    comment_map = {}
-    for comment_id, parent_id, author, text in comments:
-        comment = Comment(author, text)
+    for comment, parent_id in comment_map.values():
         parent = comment_map.get(parent_id)
         if parent is not None:
-            parent.children.append(comment)
+            parent[0].children.append(comment)
         else:
             root.append(comment)
-        comment_map[comment_id] = comment
     return root
diff --git a/templates/comment.html b/templates/comment.html
new file mode 100644
index 0000000..b988c96
--- /dev/null
+++ b/templates/comment.html
@@ -0,0 +1,19 @@
+{% macro render_comment(comment) %}
+<div style="margin-left:20px">
+	<p><i>{{ comment.author }}</i></p>
+	<p>{{ comment.text }}</p>
+	<sup><a href="{{ url_for("comment", comment_id = comment.id) }}">reply</a></sup>
+	{% for c in comment.children %}
+	{{ render_comment(c) }}
+	{% endfor %}
+</div>
+{% endmacro %}
+
+{% macro reply() %}
+{% if 'user_id' in session %}
+<form method="post" action="comment/">
+	<textarea name="text"></textarea>
+	<input type="submit" value="Post comment">
+</form>
+{% endif %}
+{% endmacro %}
diff --git a/templates/comments.html b/templates/comments.html
new file mode 100644
index 0000000..731b2e6
--- /dev/null
+++ b/templates/comments.html
@@ -0,0 +1,15 @@
+{% extends 'base.html' %}
+{% from 'comment.html' import render_comment, reply %}
+
+{% block content %}
+<sup><a href="{{ url_for('thread', thread_id = thread_id) }}">thread</a></sup>
+{% if parent_id %}
+<sup><a href="../{{ parent_id }}">parent</a></sup>
+{% endif %}
+
+{{ reply() }}
+
+{% for c in comments %}
+{{ render_comment(c) }}
+{% endfor %}
+{% endblock %}
diff --git a/templates/thread.html b/templates/thread.html
index a3d2d5e..aa977e0 100644
--- a/templates/thread.html
+++ b/templates/thread.html
@@ -1,14 +1,5 @@
 {% extends 'base.html' %}
-
-{% macro render_comment(comment) %}
-<div style="margin-left:20px">
-	<p><i>{{ comment.author }}</i></p>
-	<p>{{ comment.text }}</p>
-	{% for c in comment.children %}
-	{{ render_comment(c) }}
-	{% endfor %}
-</div>
-{% endmacro %}
+{% from 'comment.html' import render_comment, reply %}
 
 {% block content %}
 {% if manage %}
@@ -20,6 +11,9 @@
 {% endif %}
 <p>{{ author }} - rjgoire</p>
 <p>{{ text }}</p>
+
+{{ reply() }}
+
 {% for c in comments %}
 {{ render_comment(c) }}
 {% endfor %}