The Doctor, eccentric scientist and time-traveller extraordinaire, lands on an unpolluted, serene world in the late 22nd century, in an effort to relax and recover from his 7th regeneration and his recent ordeal on Earth. If your definition of relax means getting shot at by snipers, attacked by ZEDs, blown up by bullets, and getting mixed up with a crazy group of colonists, then you might say he succeeds pretty well. It's no picnic for the members of Eden Advance, either, for they are put to the test. They have to reach deeper than ever before, and take one hit after another like they rarely have. It's a situation of move and clever countermove, as the Doctor joins forces with Eden Advance to outwit a ruthless, calculating ZED which seems indestructible, and which won't stop until its mission is achieved.

The Doctor in his first incarnation, with his white hair and crotchety, impatient manner, lands on G889. But when the TARDIS doors open, out steps the Doctor in his fourth incarnation, with his dark curly hair, scarf, jelly babies, and jokes delivered at the speed of light. What's going on?

Eden Advance is still waiting for a colony ship which is three months late. What they get instead is a Time Lord who's about to meet them before they met him last year. They also get the Time Lady Romana with her dry wit, and the deadpan delivery of a robotic dog.

There's also Alonzo's regret and guilt over the Roanoke's crash; a new breed of warp-tunnel spider; a race of aliens who don't know what's happening to them; a saboteur and murderer running around the colony ship; and the threat of a fiery death in the atmosphere for everyone on colony when a double-double-cross comes to fruition. And even if they survive, the Doctor has an appointment with the planet 300,000 years ago.

And then – trouble really hits.

The Doctor has visited the world of Earth 2 three times, and now it's time to turn the tables on Eden Advance. Like dinner guests returning the favor, it's their turn to visit the world of Doctor Who. This means they get to learn about cheesy villains and plots to take over the universe.

The Doctor has been placed on trial for his life by his own people, and the members of Eden Advance have been called as witnesses – even though most of the Doctor's people look down on them for being merely humans, not Lords of Time like themselves. But why is the Castellan, a good friend of the Doctor's, pressing charges so ruthlessly when the crime could be excused? Why is the source of his information being kept a closely guarded secret? What was the Doctor's crime, and how did the Time Lords find out about it? The answers are unraveled, but not before tragedy strikes, and suddenly, Eden Advance is caught in the middle as an invading army dares to take on the most powerful race in the cosmos.

But while the Time Lords are the most powerful, they also find that they are the most lethargic. When pain and violence comes to a ten-million-year-old civilization which is supposed to be perfectly protected, the Time Lords find themselves helpless – in much the same way that Uly's immune system was unable to keep him from getting sick, when he was supposedly protected from all illnesses back on the stations. With no disease, the immune system goes away, leaving the body vulnerable when disease finally strikes. Likewise, the perfectly safe world of Gallifrey is most vulnerable when the defenses are finally breached. In all their history, the Time Lords have rarely had to fight for their planet and for their right to live – and the lowly humans of Eden Advance may just have the answers they need.