Odd Squad
There are 13 episodes in Season 3B. In the twentieth episode of Season 3, Opal left the Mobile Unit to join her sister because she was no longer evil. In the next episode, "Odd Off the Press," the Big O went to space to help the Odd Squad Space Unit and left the show after seven years. She sent the Little O to help the Mobile Unit. Opal was replaced by Agent Osmerelda, who was in many episodes as a normal child character. She did not join Odd Squad before this episode because she had too many other activities to do.