Sign-ups for round 13 close tomorrow (Friday), so if you want to participate and still haven't signed up, you should do so soon. As always, you can sign up as long as there isn't a big red "Sign-ups are closed" on the sign-up post. You can sign up
here. You can also still
sign up as a beta reader for other participants.
You will receive an email with your assignment on Sunday (or Monday at the very latest).