Prelax

Prelax was a planet which the Fifth Doctor, Peri Brown and Erimem visited. There was a costume ball which the Doctor advised Peri and Erimem from going to, but they went there anyway. Peri planned to wear Leela's outfit, but decided against it. In the meantime, the Doctor had to escort the Grand Dowager back to her palace. (BFA: No Place Like Home)