The Terror comes to its bloody end with the fall of Robespierre. The Doctor and his companions will be lucky to avoid being swept up in the violence.
The Doctor's friends are imprisoned again. To free them, he may have to betray them.
The Doctor meets with First Citizen Robespierre. Barbara, Ian and Susan are safe. But plots are afoot that endanger all of themâ€¦
Ian, Barbara and Susan try to escape their appointments with the guillotine. Meanwhile, the Doctor assumes a new identityâ€¦
Ian, Barbara and Susan are taken to Paris and sentenced to death. The Doctor is in pursuit but may not be able to reach them before they become victims of the guillotineâ€¦
The Doctor tries to return Ian and Barbara to their own time and they find themselves in Revolutionary France. It isn't long before they are caught between escaping aristocrats and blood-thirty soldiers.
Trapped on the Sense-Sphere, the Doctor and his companions find three deranged human survivors who have been fighting a guerilla war against the Sensorites.
Trapped on the Sense-Sphere, the Doctor's investigations into the cause of the sickness affecting the Sensorites are hampered by the subversive activities of the City Administrator.
Trapped on the Sense-Sphere, Ian is dying from the illness that has been killing the Sensorites and the Doctor tries to find a cure.
The Doctor and his companions are escorted to the Sense-Sphere where they attempt to negotiate with the Sensorites for the release of the TARDIS.
The Doctor and his companions are on board an Earth ship trapped in orbit around the Sense-Sphere when it is boarded by the Sensorites, who have stolen the lock mechanism from the TARDIS.
The 28th century. The TARDIS materialises on a spaceship orbiting a planet known as the Sense-Sphere, whose natives, the Sensorites, have trapped the ship's human crew in a state of paralysis.
Ian, Barbara, Susan, Altos and Sebetha arrive in a jungle and begin to search for the next key. The group soon finds out that their task is fraught with danger.
The Doctor and his companions arrive on the planet Marinus. Within a pyramid, surrounded by an acid sea, rests a machine capable of bringing peace and order to the planet. Its keeper holds off the evil Voord and wants the Doctor and his crew to retrieve the missing circuits to reactivate it. They may have no choice but to comply...moreless