Friday, 6th January 1984 6:40PM BBC 1 (24 mins)
The Sea Devils launch their attack on Sea Base 4 with the Doctor and Tegan inside. The Doctor’s attempt to broker peace fails and the Sea Base retaliates with a missile attack which backfires badly. The Silurians then send the Myrka, a giant reptilian machine, to attack one of the base’s airlocks.