From the
Radio Times:
5.50 ColourDr Who
starring
Jon PertweeThe Mutantsby BOB BAKER
and DAVE MARTIN
Part 2
Jo is a hunted fugitive on the poisonous surface of Solos. The Marshal blackmails the Doctor into helping him with his plans.
MarshalPAUL WHITSUM-JONES
Dr WhoJON PERTWEE
CottonRICK JAMES
Jo GrantKATY MANNING
KyGARRICK HAGON
StubbsCHRISTOPHER COLL
JaegerGEORGE PRAVDA
Varan's sonJONATHAN SHERWOOD
VaranJAMES MELLOR
Title music by RON GRAINER
and the BBC RADIOPHONIC WORKSHOP
Incidental music by TRISTRAM CARY
Script editor TERRANCE DICKS
Designer JEREMY BEAR
Producer BARRY LETTS
Director CHRISTOPHER BARRY