Three Doctors

A signal was sent to the Earth at superluminal speed, carrying an unusual clot of energy, which, it seems, intends to capture the Doctor. At the same time, the home planet of the lords of time is under siege: all the energy goes through a black hole. In desperation, they violate their First Law of Time and allow the Doctor to help himself by invoking his two previous incarnations from the past. But the Second and Third can not work together in any way and are constantly bickering, so they ask the First to call them to order.

Unfortunately, the First Doctor finds himself in a whirlwind of time and can only communicate through a communicator, but the Second all the same joins the Third in the study of the origin of the creature and the black hole, and in the meantime, UNIT headquarters is attacked by gel-like aliens.

The first guesses that the black hole is the bridge between the universes, and the rest decide to allow the creature to absorb the TARDIS - thus in the universe of antimatter created by the time lord Omega, they both end up, Dr. Tyler, Joe Grant, Sergeant Benton and the foreman Lethbridge-Stewart. Omega was a solar energy specialist who created a supernova that nourishes the entire civilization of the lords of the time, and was considered dead when it exploded. But in fact, he was transferred to the universe of antimatter, where his will and thoughts were embodied from formless matter. Finding himself in prison, realizing that only his will holds this world, he began to go crazy and vowed to take revenge on the lords of the time who left him. Following the plan of revenge, he called on the Doctors to shift onto them the retention of the form of the universe, and in the meantime leave. But it turns out that the physical body of Omega due to the corrosive effects of the black hole was destroyed, and he was stuck here forever. Then he decides that the Doctors will share his exile.

The second and third offer freedom to Omega if he lets the rest go home. Omega agrees and, after being sent, the Doctors hand him a force field generator with a Second flute inside, which during transportation did not turn into antimatter. In a rage, Omega kicks the generator, and the flute falls out of the force field, contacting antimatter and annihilating everything. Doctors fly away to the TARDIS in their native universe, and the Third says that death is the only possible freedom for Omega.

The energy of the lords of time is restored, and they send the First and Second to their timelines, and the Third, as a reward, they are presented with a new dematerialization circuit for TARDIS and restore his knowledge of travels in space and time.

• This series is interesting in terms of the intersection of timelines. Although in this series it is not mentioned that the First and Second Doctor lost their memory in this adventure, this is implied, because otherwise the Third Doctor would have remembered the resolution of the situation from his predecessor.
• In this series, the First Doctor performed by William Hartnell appears for the last time. Already during the filming, he was seriously ill, which is why he appeared in the frame for several minutes and only sitting.
• Initially, the appearance of Jamie McCrimmon was planned for the series, but actor Fraser Hines was busy filming the soap opera Emmerdale Farm . The functions of his character in this series were assigned to Sergeant Benton.