The first part of the 1972 Jon Pertwee classic The Sea Devils airs tonight on BBC Two.

The Radio Times says:

A six-part sci-fi adventure from the 70s, starring Jon Pertwee 1: Jo (Katy Manning ) and the Doctor visit the evil Master (Roger Delgado ) who is locked up in an island prison. Or is he? Episode written by Malcolm Hulke Producer Barry Letts. Director Michael Briant. TELETEXT SUBTITLES: page 888.

The Sea Devils Episode 1 airs tonight at 6:50pm on BBC Two.