The Doctor's been everywhere and everywhen in the whole of the universe and seems to know all the answers. But ask him what happened to the Starship Brillant and he hasn't the first idea. Did it fall into a sun or black hole? Was it shot down in the first moments of the galactic war? And what's this about a secret experimental drive? The Doctor is skittish. But if Martha is so keen to find out he'll land the Tardis on the Brilliant, a few days before it vanishes. Then they can see for themselves...
1500BC - King Actaeus and his subjects live in mortal fear of the awesome gods who have come to visit their kingdom in ancient Greece. Except the Doctor, visiting with university student June, knows they're not gods at all. They're aliens! With June's enthusiastic help, the Doctor soon meets the travel agents behind this deadly package holiday company - his old enemies the Slitheen! But can he bring the Slitheen excursion to an end without endangering more lives?