Where is the threading?
Some people new to the forum are at first confused about how it displays messages in a topic (which is called a “thread” in many systems). Messages are presented in the order that they were written, but don’t worry. You can still see how the conversation unfolded.
Just a reply
If a reply is in response to the message immediately above it, there is no special marker.
Seeing the context
Replies to other messages include an arrow and the avatar of the person being replied to (). If you click the arrow that post will be expanded in place; if you want to go back to see that post in its original context, you can click the and the browser will scroll back up to that message.
Similarly, if someone replies to a message, there is an indicator (like ). You can click to see those replies immediately under the topic and then click to jump down to that part of the discussion.