London, 1963

Die Lehrer Ian Chesterton und Barbara Wright sind über das Verhalten einer ihrer Schülerin, Susan Foreman, verblüfft. Ihre Kenntnisse in Wissenschaft und Geschichte übertreffen ihre, dennoch scheint sie viele Aspekte des Alltags nicht zu kennen. Sie folgen ihr zu ihrer Wohnadresse, einem Schrottplatz mit einer Polizeitelefonzelle, und treffen dort auf ihren Großvater, den rätselhaften Doktor. Als sie sich an ihm vorbei in die Notrufzelle drängen, wird Susans Geheimnis gelüftet: Sie und der Doktor sind Außerirdische, und die Polizeitelefonzelle ist eine Zeitmaschine, die TARDIS, die jeden Punkt im Universum zu jedem Zeitpunkt besuchen kann…

Erde, 100.000 v.

Der rätselhafte Doktor, der befürchtet, dass die Lehrer Ian Chesterton und Barbara Wright den Menschen auf der Erde des 20. Jahrhunderts seine Geheimnisse enthüllen werden, hat sie und seine Enkelin Susan in die Anfänge der Menschheitsgeschichte zurückversetzt. Dort werden die vier Reisenden in die wilde Politik eines Stammes von Höhlenmenschen hineingezogen, die das Geheimnis des Feuermachens verloren haben…

Als Gefangene der frühesten Menschen wird die TARDIS-Crew in ein tödliches Machtspiel um die Führung des Stammes verwickelt.

Zeit unbekannt, Planet unbekannt. Die TARDIS landet in einem unheimlichen versteinerten Wald mit Blick auf eine prächtige Stahlstadt. Der Doktor will die Stadt erkunden – doch was wartet dort?

Der tote Planet ist doch nicht bewohnt. Der Doktor ist im Begriff, seinen größten Feinden zu begegnen. Während dessen sterben er und seine Mitreisenden an Strahlenkrankheit.

Auf Skaro, eingesperrt von den intriganten Daleks, arbeiten der Doktor und seine Gefährten daran, ihren Fängen zu entkommen.

Die Zeitreisenden arbeiten verzweifelt daran, der Stadt der Daleks zu entkommen und ein blutiges Massaker zu verhindern.

Die Zeitreisenden sind den Daleks entkommen, haben aber ein wichtiges Stück der TARDIS zurückgelassen. Es zurückzubekommen bedeutet, die Thals zu einer gefährlichen Operation zu drängen.

Ian, Barbara und die Thals kämpfen sich durch die Höhlen, um die Stadt der Daleks zu erreichen. Werden sie rechtzeitig dort ankommen? Gibt es überhaupt einen Weg durch die tückischen Höhlen? Und was planen die Daleks?

Die Zeit läuft davon, als der Doktor und seine Gefährten versuchen, die Daleks zu besiegen, bevor sie alles Leben auf Skaro auslöschen.

Eine mysteriöse Explosion hat die TARDIS ins Leere geschleudert. Und in ihrer Verwirrung beschuldigen sich die Zeitreisenden gegenseitig.

Die TARDIS treibt umher, die Crew geht gegeneinander an. Nur gemeinsam können sie ihren Weg finden, bevor sie zerstört werden.

The TARDIS experiences a total power failure and is stranded in the Himalayas in the 13th century. The travellers are forced to join the caravan of the famous explorer, Marco Polo, in order to survive -- but Polo, fascinated by their claims that the TARDIS can fly through the air, seizes it on behalf of Kublai Khan in the hope that presenting the Khan with such a fabulous gift will convince him to let Polo return home to Venice. The travellers are forced to accompany Polo on his long trek across Asia to the Khan's court, but their many attempts to reclaim their property are foiled -- not just by Polo, but by the war lord Tegana, who is apparently on a mission of peace but has entirely different plans for dealing with Kublai Khan...

Tegana sabotages the party's water bags, leaving them in dire need of fresh supplies.

The Doctor and Susan are able to supply Marco with condensation that has formed inside the TARDIS, saving the group from dying of thirst. When the group are reunited with Tegana, the travellers begin to suspect he is up to something.

The Doctor's group manage to rescue Barbara from the Mongols but once more Marco remains unaware of Tegana's involvement.

The Doctor and his friends elect to warn Marco of Acomat's attack even though it means losing their chance to gain access to the TARDIS.

The Doctor, Ian and Barbara are forced to surrender to Tegana and Marco, leaving both of them the opportunity to gain possession of the TARDIS.

Tegana finally makes his move to assassinate the Khan, giving the Doctor and his friends an opportunity to thwart his plans and regain the TARDIS.

The alien world of Marinus. Perfect peace has reigned here for decades due to the mind-controlling influence of a machine known as the Conscience. But now a race known as the Voord have developed an immunity and Arbitan, keeper of the machine, has been forced to scatter the vital control keys around the planet. Now he needs the help of the time travellers to get them back - it will be an extraordinary journey, with perils every step of the way...

The Doctor and his friends arrive in the apparently idyllic city of Morphoton but Barbara soon begins to realise there is more to their hosts than meets the eye.

The search for the second key takes the travellers to a jungle where Ian and Barbara come under threat from rapidly growing plants.

Searching for the third key, Ian and Barbara meet with the sinister trapper Vasor before following Susan and the others into a cave system guarded by the mysterious Ice Soldiers.

The group are reunited with the Doctor in the city of Millennius where Ian faces trial for murder after the fourth key is stolen.

The Doctor and his friends must locate the real murderers and the fourth key before heading off for a final confrontation with the Voord

The TARDIS arrives on Earth landing in 16th century Aztec society. Barbara goes off exploring - despite the Doctor's orders not to wander off - and is taken away by the high priest Autloc who believes she is the reincarnation of the goddess Yetaxa. They believe it is a sign that the rains - which are late - will now come. The high priest of sacrifice Tlotoxl recruits Ian to lead their army but he finds he has a rival in Ixta. Ian is less than comfortable with his role when he learns that they are to deliver the human sacrifice to the high priest at the rain ceremony. The Doctor emphasizes that they must not interfere with Aztec rituals, something that does not sit well with Barbara.

Barbara tries to change the course of history - and Ian fights for his life.

While the Doctor tries to find a way back to the TARDIS, Tlotoxl continues to plot Barbara's downfall and sees an opening when Susan questions Aztec custom.

Tlotoxl's machinations result in both Susan and Ian being arrested. With the TARDIS once again trapped inside the tomb, the travellers' only hope for escape lies with Autloc and Cameca.

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.

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 steal the lock mechanism from the TARDIS.

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.

With Ian having fallen victim to the Sensorites' plague, the Doctor is desperate to find a cure. But the City Administrator is still determined to rid his world of aliens.

The City Administrator is determined to destroy the Doctor and his friends and his paranoia prevents the Doctor's cure from being distributed.

While the City Administrator's schemes reach their climax, the Doctor and Ian venture into the tunnels under the city to discover the real cause of the Sensorite plague.

The TARDIS lands during the French Revolution, where Ian, Barbara, and Susan become caught up in the politics of the day. When they are arrested and set to be executed, the Doctor must take on the disguise of a public official to try and save their lives.

Susan, Ian and Barbara are sentenced to be guillotined but an encounter with a dying English prisoner may offer Ian a chance of survival.

Susan and Barbara are rescued by Jules and Jean, two members of the escape chain, while the Doctor gains access to the prison by posing as a revolution official.

The Doctor is forced into a meeting with Robespierre while Barbara's attempts to find a physician for Susan result in them being betrayed.

Ian finds himself held prisoner by the treacherous Leon while the Doctor attempts to engineer Susan and Barbara's escape.

Ian finally delivers his message to James Stirling but in order to secure Susan's release he and Barbara are forced into a dangerous spying mission.