4/6 The Marshal prepares to bombard Solos with ionisation rockets.
3/6 Ky opens the message box but is unable to understand the ancient carved tablets inside.
2/6 Fearing Jo has died on Solos, the Doctor is forced to make its atmosphere breathable.
1/6 On the Skybase above Solos the Marshal wants to stop the planet achieving independence.
6/6 The Sea Devils come to the surface and attack the Naval base.