First Doctor
In 1963 London, a young woman named Susan Foreman aroused the suspicions of two of her teachers (Ian Chesterton and Barbara Wright) for her brilliance, but also for her seeming incomprehension of "modern" England such as pre-decimal currency. The pair follow her "home" and she disappears into a junkyard containing a large blue Police Box. Ian and Barbara hear Susan's voice from the box and enter, only to discover that it is bigger on the inside than outside. It is the TARDIS, a time machine operated by Susan's grandfather, the enigmatic Doctor, who promptly kidnaps the two teachers for fear of them revealing his and Susan's secret.
The Doctor, with the unwilling teachers in tow, have an adventure in Stone Age earth before traveling, at random., to the planet of Skaro where they meet the Daleks, one of the Doctor's greatest foes, for the first time. In this time, the salt shaker-shaped Daleks are are at war on their home planet with the Thals. The Doctor helps the Thals defeat the Daleks, but they would be back again for uncounted adventures. Returning to traveling, the Doctor and his companions nearly kill each other after a malfunction on the TARDIS causes them to lose their memories, but they repair the problem. Subsequent adventures include losing the TARDIS to Marco Polo in 1289, an alien scavenger hunt on the planet Marinus, having Barbara mistaken for a Goddess by the Aztecs in the 1400s, helping out 28th century humans, being caught up in the French Revolution, and being shrunk to miniature on modern Earth.
Finally returning to London, Ian and Barbara believe that they can go home, only to find that the city is in ruins and the date is 2163. In this future, the Daleks have invaded Earth, many humans have been enslaved as Robomen, and a small group of freedom fighters plot against their occupiers. Naturally, the Doctor and his companions help out and eventually overthrow the Daleks, restoring freedom to the Earth. During this adventure, Susan falls in love with David Campbell, one of the freedom fighters, and she elects to remain on Earth to help rebuild. The Doctor, Ian, and Barbara leave without her in the TARDIS.
The Doctor next travels to the planet Dido in the 25th century where he discovers two human survivors of a spaceship crash: Vicki and Bennett. Vicki is a normal Earth teenager who was traveling with her family. They are being stalked by a native creature known as the Koquillion which killed all the other crash survivors. After a brush up with the breast, the Doctor discovers that the "Koquillion" is actually Bennett, who is killing the other survivors to cover up a crime. The Doctor puts a stop to this and offers to let Vicki travel with him and she agrees, becoming his fourth companion.
Vicki, Ian, and Barbara continue adventuring: first to ancient Rome, to the planet Vortis where they discover the insect-like Zarbi, onward to Jerusalem during the Third Crusade, and then to a space muesum on the planet Xeros. In their next adventure, the trio travel to a desert planet where they find that Daleks (traveling in their own time machines) are set to execute the Doctor. After eluding the Daleks, the Doctor and his companions are able to return to the TARDIS and escape, with the Dalek's right behind. In a series of quick encounters, the Daleks chase the TARDIS through several points in time: New York in 1966 (on top of the Empire State Building), the ill-fated voyage of the Mary Celeste in 1872, and a future theme part in 1996. While at the theme park (with robots modeled on Frankenstein and Dracula), Vicki sneaks on board the Dalek ship and is believed to have been kidnapped. While on a jungle planet, the Doctor, Ian, and Barbara plot her rescue. The jungle planet is actually being prepared by Mechanoids, robot servants created by future humans, for future colonization. A human astronaut from the future, Steven Taylor, has also been captured by the Mechanoids. Through several contrivances, the Doctor and Vicki is reunited, they team up with Steven to escape the Daleks, and the Mechanoids enter into a pitched battle with the Daleks. In the confusion, Steven is presumed killed (though he actually stows away in the TARDIS, becoming the fifth companion) and the others escape. Ian and Barbara are permitted to use the Dalek's time machine to return to Earth in 1965 and the Doctor and Vicki venture on alone.
Not long after, the Doctor and Vicki discover their stow-away and they travel onward to England in 1066 where the group prevent a fellow Time Lord from altering England's past and then back to the future where they barely survive the destruction of a planet populated by robots. In their next adventure, the Doctor and his companions travel back to ancient Troy, ten years into the Trojan War. The Doctor,, after briefly being thought of an an incarnation of Zeus, is ultimately accused of being a Trojan spy. Steven goes on after the Doctor, leaving Vicki in the TARDIS. Although the Doctor is able to prevent himself and Steven from being killed by the Greeks, the Trojans are able to capture the TARDIS with Vicki still inside. Steven gets himself captured by the Trojans and is able to rejoin Vicki while the Doctor gives the Greeks the idea of building the Trojan Horse. During the ensuing battle, Steven is badly wounded and is rescued by Katarina, a Trojan handmaiden who had befriended Vicki. They all escape to the TARDIS, but Vicki has fallen in love with a Trojan prince and, with the Doctor's permission, they escape together. Still believing that the Doctor is a God and that the TARDIS is his temple, Katarina joined the Doctor as his sixth companion.
