Episode ThreeSeries Episode Number: 340
World Premiere: Sat 10 Mar 1973 - 5:52pm GMT [BBC One] (United Kingdom)
Running Time: 24 minutes
7.50 Million (UK)
Chart Position: 57 () (UK)
Recorded on Mon 16 Oct 1972 in TC3
Archive State: PAL 2 VT
Accused of being a spy, the Doctor is sentenced to imprisonment on the Moon while Jo is taken into the custody of an old enemy.