The modern era of
Doctor Who has a reputation of killing off companions to end their tenure. However, that’s not actually true… in the modern era, only Clara and Bill died (technically Amy and Rory were sent to the past, not killed). That being said,
Doctor Who has a knack for removing companions in a way that they definitely can’t come back (i.e. Rose trapped in an alternate universe, Donna’s memory wiped, Amy and Rory lost in time, etc.). Even so, there are plenty of companions who left on their own accord. Two such classic companions are supposed to appear in the upcoming BBC Centenary special entitled “Power of the Doctor.” Each Doctor has at least one companion like that, so I just wanted to talk about a few of them. (Potential spoilers ahead)
Susan ForemanThe First Doctor’s first companion (as far as we know) was his granddaughter Susan. It was because of her that the Doctor started traveling around with humans, after Ian and Barbara stumbled into the TARDIS. Susan was left behind in the 22nd Century to be with a man she’d fallen in love with. The First Doctor promised he’d return for her and I don’t think their encounter during The Five Doctors counts.
Ben Jackson and Polly WrightOriginally traveling with the First Doctor, Polly and Ben were around for his regeneration into the Second Doctor. However, the two later returned to their lives in 20th Century England. According to some reports, they got married eventually and based on Sarah Jane’s recollection, they were running an orphanage in India. So what’s to stop the Doctor dropping into 21st Century India and picking up a couple of old friends?
Jo Grant JonesShe was my favorite of the Third Doctor’s companions, but she also had the opportunity to work with the Second and the Eleventh Doctors. While with UNIT, she met and married her husband, leaving UNIT and the Doctor in the process. However, we know that in later years, after having kids and grandkids, Jo met Sarah Jane Smith and the Eleventh Doctor at his funeral. She and Eleven ended on good terms, so why not drop into the Amazon (or wherever Jo finds herself) and incorporate her and/or her family into a story?
Harry SullivanEDIT: I was corrected after initially writing this post; Ian Marter, who played Harry, died in 1986. So while the character is alive as of Sarah Jane's comment, he wouldn't return.
As a UNIT employee, he only traveled in the TARDIS for a short time, but he left his impression on Sarah Jane Smith. A doctor himself, Sarah Jane recalled that he spent his time after the Fourth Doctor and (presumably) UNIT, he was instrumental in developing and distributing vaccines to many people, saving lives. With the supposed return of UNIT personnel in the Centenary special, it would be plausible for Harry to appear. Unlikely, but plausible.
Tegan JovankaFirst an unwitting companion of the Fourth Doctor, Tegan later traveled willingly with the Fifth Doctor. But the destruction he left in his wake became too much for her. She left the TARDIS (regretting it almost instantly). Her post-TARDIS life was spent campaigning for Aboriginal rights… until this month. We don’t know in what capacity she’ll appear… but she’s returning to team up with the Thirteenth Doctor and some other friends.
Melanie BushHer history is a bit muddled (wibbly wobbly timey wimey stuff) but as far as we know in the current timeline, she began traveling with the Doctor during his trial on Gallifrey. She continued with the Seventh Doctor, eventually staying in the distant future to travel. Unlikely to appear in the Centenary special, but who knows for future Doctors and future stories?
Dorothy “Ace” McShaneWe don’t know what happened to Ace after the end of the classic era of Doctor Who and why she left the TARDIS. However, her time with the Seventh Doctor is one of my favorite eras of Classic Who. When I met Sylvester McCoy and asked him about Ace, he said he likes to think she got into politics and made a difference that way. Sarah Jane, however, noted that a woman named Dorothy ran a charity organization, later seen in this clip. So as such, I’m excited to see Ace return for the special, alongside Tegan and others.
Grace HollowayShe only appeared on screen for the TV movie, but spin-off material would suggest that the Eighth Doctor had more interactions with Grace after their Y2K scare. Very few American companions have traveled with the Doctor, but Grace could have been the first (unless you count Peri and her poor accent). Still, as far as we know, she’s still in the United States, probably still in San Francisco, helping and maybe waiting for the Doctor.
Captain Jack HarknessWe’ve seen Captain Jack return multiple times since he was a regular TARDIS companion. After the Ninth Doctor left him behind, he teamed up with the Tenth Doctor (on multiple occasions) and the Thirteenth Doctor. Because of how Rose resurrected him, he’s not dying any time soon… so you never know when Captain Jack could return.
Martha JonesAfter falling for the Tenth Doctor, she left the TARDIS, finished med school, and joined UNIT. I’ve never seen Torchwood, but apparently she shows up there too. She’s never been my favorite companion… I actually thought she was kind of bland during her time with the Tenth Doctor… until she left and returned. She definitely had some growth throughout her time on the show and she’s definitely done well for herself since leaving the TARDIS. So I wouldn’t mind a return visit from Dr. Jones (or it might be Dr. Jones-Smith now).
Clara OswaldI know she already died, technically. But that version of Clara plucked between heartbeats could still be traveling around time and space with Me. So while Clara is dead in London in the present day, there’s no stopping them from bringing her back again. Especially since the Twelfth Doctor had his memories of her restored shortly before he regenerated. Or at the very least, why not have a splinter of Clara (like Oswin) show up?
Nardole He was kind of an odd choice of companion for the Twelfth Doctor, but I'll always be grateful for the comic timing he brought to the TARDIS team. He's also the only properly living companion of the Twelfth Doctor... granted he's part cyborg, but still. After the encounter with the Mondasian Cybermen, he stayed behind to help a fragment of human civilization still recovering. Though in some ways he was just left behind. At any rate, the Doctor could return to that ship and retrieve Nardole if he/she wanted.
Graham O’Brien and Ryan Sinclair The most recent companions to leave the TARDIS. The Thirteenth Doctor left them with a psychic paper and a charge to protect the Earth. How literal she was about that… who knows? But we do know Graham will return for the Centenary special. Ryan, no word yet. But you never know what’ll happen at a later date.
In the meantime, I’m looking forward to the return of Tegan, Ace, and Graham. Now excuse me while I finish rewatching Series 13 in preparation for next month.