A gel-like plasma creature arrives on Earth and hunts down The Doctor, who calls on The Time Lords for help. The Time Lords themselves are in crisis as their energy is being drawn off into a black hole. They send The Doctor’s earlier selves to join him. The first Doctor, caught in a time eddy and able only to advise, deduces that the creature is a time bridge.
The third Doctor and Jo then give themselves up to it and are transported to a world of antimatter beyond the black hole.On Earth, the second Doctor is forced to take refuge in the TARDIS along with the Brigadier and Sergeant Benton. He switches off the ship’s force field, and the whole UNIT building is transported through the black hole.
Behind these events is Omega, a figure from the Time Lord history whose solar engineering provided the power for time travel.
If the Time Lords could just pull The Doctor out of time as easily as they could here, the question is why they couldn’t have used this while he was on the run from them in his previous two incarnations.However, back then they didn’t know where The Doctor was at the present, whereas they knew it here, so it is possible that they need to have something to ‘work backwards’ from, if you will.
