Warning: Spoilers ahead for Doctor Who season 15, episode 6, "The Interstellar Song Contest."Doctor Who season 14's cast, it became increasingly obvious what kind of Doctor Fifteen wanted to be, and that has continued into season 15. However, there's something else below the surface.

As the first new Doctor of David Tennant's Tenth Doctor or Matt Smith's Eleventh. He's also recognizable for his vast and fashionable wardrobe, as opposed to boasting a single recognizable hero costume. He's also a little quicker to tears than his predecessors. While I don't doubt that all these traits are authentic to Fifteen, Doctor Who's Eurovision episode shows something additional and worrying.

Doctor Who Season 15, Episode 6 Fully Reveals The Fifteenth Doctor's Darker Side

Fifteen's torture sequence shows the Doctor at his worst

The Doctor tends to avoid cruelty for the sake of cruelty, and often strives to keep pain and violence at bay if it can be avoided. That said, there have been several instances throughout Doctor Who's multi-decade history where the Doctor has fallen victim to darker urges and is driven by colder motivations than simply saving the day. "The Interstellar Song Contest" is the purest example of one of these scenes for Fifteen, as he's clearly reveling in the torture of the episode's villain, Kid (Freddie Fox).

Doctor Who season 14, episode 1, "Space Babies," was the first time I noticed Fifteen's dark side trying to get out. It's only a brief moment, but end of "Dot and Bubble." Torturing Kid is the first time I've seen Fifteen completely surrender to this side of himself.

After so many teases of this trait within Fifteen, it's rewarding to see it pay off.

I love seeing the Doctor acting heroically, but it's always interesting when the Time Lord acts unexpectedly. In a way, the scenes in question suggest that the audience doesn't know the Doctor quite as well as assumed, or that the Doctor's less endearing traits are conveniently forgotten or ignored. These moments shine a light on the Doctor's fallibility, as well as his blood-soaked history in the Time War and other conflicts that have taken place within Doctor Who canon. After so many teases of this trait within Fifteen, it's rewarding to see it pay off.

Doctor Who Season 15 Explains Why Fifteen's Dark Side Comes Out

Fifteen's triggers include being reminded of the Time War & the loss of Gallifrey

periods of the Doctor's life where he has been without a companion, he tends to slip into a slightly darker persona and be quicker to irrational actions and even violence. His hearts are almost always in the right place in these instances, but he tries to take a destructively straight line to what he believes at the time to be a just victory.

Kid's planned genocide of the three trillion viewers of the episode's titular contest instantly brings to mind the death of Gallifrey.

Belinda Chandra (Varada Sethu) becomes separated from the Doctor in "The Interstellar Song Contest," and the chaotic goings-on lead Fifteen to falsely believe that his companion has died. So, this ticks the box of not having a friend to keep him on the correct path, but it also crosses over into another of the Doctor's dark-side triggers. Kid's planned genocide of the three trillion viewers of the episode's titular contest instantly brings to mind the death of Gallifrey and all of the Doctor's people.

The scenarios in question have been when Fifteen is struggling to save more lives than usual.

So, paired with the fact that he's essentially flying solo for huge portions of the episode, it starts to make more sense that Fifteen loses so much control and tortures Kid. Other occasions when Fifteen's darkness has been on show, like in "Dot and Bubble," and even killing Sutekh in "Empire of Death," haven't included a companion-less Doctor. However, the scenarios in question have been when Fifteen is struggling to save more lives than usual. These situations seem to make his composure slip because of what happened to Gallifrey, and he strays quite far from the rails as a result.

Ncuti Gatwa's Fifteenth Doctor Having A Darker Side Makes Him Much More Interesting

Gatwa's Doctor is now following in the footsteps of his predecessors closer than ever before

I love Ncuti Gatwa as the Doctor. I'd never seen him in anything before his casting in Doctor Who, so I was able to perceive him solely as the Doctor right from the start without previous experiences affecting my perceptions. He plays the fun and lighthearted moments incredibly well, and I think the flirtatious streak he's brought to the character is an unexpectedly brilliant acting choice. That said, I don't think all of that would have been enough to hold his iteration of the Time Lord together as a complete and well-rounded character.

Many of my favorite Fifteenth Doctor scenes so far have been when all I can see is a thirst for vengeance in his eyes.

If anything, Fifteen's generally less intense demeanor perfectly sets up the moments when his dark side shows through the cracks. It's tough to see them coming, and held up against how he usually plays the Doctor, the scenes in question stand out in the best possible way. Many of my favorite Fifteenth Doctor scenes so far have been when all I can see is a thirst for vengeance in his eyes, or an aggressive frustration caused by being prevented from fulfilling what he perceives as his role in the universe as the biggest protector of life through space and time.

Previous stars have one or more definitive moments that immortalize their time as the show's leading actor. Gatwa has had some good moments, especially during season 15, but I think only a few of them fit into this category. That's not a harsh criticism, as that also tends to be the case for every Doctor actor, and the scenes that endure are the ones that show the various iterations of the character losing their grip on the emotions they so often try to keep hidden away. Now, Ncuti Gatwa is starting to gather more of these memorable Doctor Who moments.