In the long history of Doctor Who, The Doctor has traveled time and space with many people for varying amounts of time. Some companions have been beloved by fans and had the end to their stories lamented, celebrated, and disbelieved. Other companions have been quietly swept under the rug or just never seen again.
In the pantheon of The Doctor's companions who had the best exit? Whether it was a fitting end for their character arc, an insane and bombastic ending, or a sad and melancholy dispatch, let's look at the best sendoffs from the 60-year history of the show.
Jamie & Zoe
Jamie McCrimmon (Frazer Hines) was a companion who joined the Second Doctor from the highlands of Scotland in the 18th century. Jamie joined the Doctor after the English defeat of the Jacobite Rebellion at the Battle of Culloden. Zoe Heriot (Wendy Padbury) was a scientist from the 21st century who joined the Doctor and Jamie after helping them to defeat the Cybermen who are aiming to invade Earth.
Both Jamie and Zoe exited the series in the same episode, the concluding episode of series 6 titled "The War Games." The episode was a first for the series for several reasons. It marked the first time companions had departed in the final episode of a series, and it was the first time the entire main cast was changed at once, as Patrick Troughton also departed the show, paving way for the Third Doctor.
Not only was it an episode with a full cast changeover, but "The War Games" was also the first appearance of the Time Lords and The Doctor's home planet of Gallifrey. The Doctor calls the Time Lords as a last resort when he encounters another one of his people, The War Chief, who has gone rogue. Once the War Chief is dispatched, the Time Lords catch up to the fleeing Doctor and his companions. After a trial, Zoe and Jamie have their minds wiped by the Time Lords, and are returned to the exact moment of their first appearance as though they had never met the Doctor. It is a sad ending for the trio. Zoe is feeling she is missing something, and Jamie charges into battle with the British.
Tegan
When popular companion Tegan (Janet Fielding) left the show, she left on her terms. Initially, Tegan was an unwilling companion after accidentally stowing away on the TARDIS with the Fourth Doctor (Tom Baker) and Adric (Matthew Waterhouse) while looking for help. Throughout her time on the TARDIS, Tegan made it very clear that she wanted to return to Heathrow to begin her life as an air steward. She even wore her uniform to remind the Doctor of that fact.
As a headstrong and no-nonsense companion, Tegan was beloved by audiences and resolute in her wish to return home. Her final appearance came in "Resurrection of The Daleks" after defeating the evil Davros and the Daleks, who plan to invade Earth and use clones of the Doctor and his companions to infiltrate and assassinate the Time Lord High Council. With the Daleks thwarted, the Doctor makes to leave, but Tegan refuses, saying that it was no longer fun. This may seem simple, but Tegan leaving on her terms and starting the life she wanted was an incredibly satisfying end to her run as a companion.
Adric
Overlapping with Tegan's run with The Doctor was Adric, a resident of E-Space and a brilliant mind. Unfortunately, he knew how intelligent he was, and often came across as arrogant. As such, Adric is often cited as one of the least-liked companions. However, his ending story was a redemptive and sad story that impacted the TARDIS crew greatly.
Adric's final appearance came in the serial "Earthshock," which saw Team TARDIS once again face off with the Cybermen. The Cybermen are attempting to destroy the Earth and the team comes up against them on a freighter out in the atmosphere. Once discovered, the Cybermen lock the freighter controls on a crash course with Earth and demand the Doctor takes them to escape on the TARDIS. Adric sneaks off, leaving the Doctor his gold badge for Mathematical Excellence, knowing the Cybermen are allergic to gold.
Once the TARDIS departs, the remaining crew overpowers the remaining guards as Adric attempts to override the controls. They are locked with a device that can only be unlocked with complex logic codes. After his first attempt causes the ship to time-jump backward 65 million years, his second takes the ship out of warp but still on a collision course with Earth. Before Adric can enter his third attempt, the dying Cyberman fires at him, missing and destroying the computer. Adric's final words are "Now I'll never know if I was right," before the ship collides with the Earth, killing him and triggering the extinction of the dinosaurs. His traveling friends helplessly watch his death on the viewing screen of the TARDIS.
The reason Adric's death is so important is because of the redemption it provides him as a character, and because of how deeply it affected the rest of the characters. His death greatly affected Nyssa and Tegan so much so that the Xeraphin used an illusion of Adric to try and trick them. Adric also appeared as a hallucination in a later episode, and his name was the last thing The Fifth Doctor said before regenerating.
Out of these impactful endings, Adric's exit takes the prize, but only just. How his exit showcased his strengths and growth as a character and the devastation he left behind sets his exit aside as one of the best in the history of the show.