A Master and Commander, an Officer and a Gentleman, and Tonnes of Seamen. Behold the aquatic cousins of the Silurians!
Doc and Jo are off to visit The Master, who (like a less maniacal Richard Branson) has his own island. Imprisoned there indefinitely, and with unfettered access to sabres, robes and moustache wax — not to mention the most lax prison warden ever — The Master has got it in his brain to team up with yet another non-human civilisation.
This time he has partnered with the Sea Devils, aquatic cousins of the Silurians (or Eocenes, as is rectified in this serial), to defeat mankind and reclaim this blue marble in the name of reptiles wearing chainmail everywhere. Wonder if it’s going to backfire on him.