This Doctor Who Moment Proved It Was Time For David Tennant’s Tenth Doctor To Go

David Tennant departed as Doctor Who‘s leading man at the very beginning of 2009, but there was a pivotal scene during his era that proved beyond doubt that it was time for the Tenth Doctor’s time to end. Although largely remembered for his zany and fun-loving attitude, Tennant’s version of the Time Lord wasn’t without his dark moments. The Tenth Doctor’s timeline was littered with scenes that brought these shocking character traits to the surface, but one near the end of his life was far too significant to ignore.

Of all the actors to play the Doctor, Tennant is the only one to come back as often as he has, and at such significant moments. This is a testament to just how popular he was, but it also highlights just how brilliantly Tennant played the Doctor. While Ten often seemed larger-than-life in an almost comical way, he also had many nuanced, brooding moments that took a little while to fully parse. That being said, certain scenes stick out for very worrying reasons, and one proved it was a good thing he was going to regenerate soon.

The Doctor’s “Time Lord Victorious” Scene In The Waters Of Mars Was Ten At His Most Dangerous

Ten intentionally broke many of the Time Lords’ rules in the 2008 special

By the time of 2008’s “The Waters of Mars,” Ten had been traveling on his own for at least two separate adventures. “The Day of the Doctor” has also been revealed to have happened to Tennant’s Doctor around this time, so there are likely more stories unaccounted for. The impact that the Doctor’s time alone has had on him is evident in “The Waters of Mars.” He hasn’t had anyone to stop him from following every impulse, and the episode shows him being heroic to the point of fault.

He goes several steps too far and prevents what should be a fixed point in the timeline by saving Lindsay Duncan’s Adelaide Brooke from perishing on Mars. Adelaide’s death would have influenced the future of human space exploration, but the Doctor seems unconcerned by his massive intervention, declaring himself the “Time Lord Victorious.” What Ten perceives as an act of mercy ultimately becomes nothing more than a failed and unknowingly cruel rescue attempt.

Rather than dying as a hero due to unknown causes on Mars, Adelaide sadly feels obliged to correct the timeline by taking her own life at the end of the episode. It’s this extreme solution that brings the Doctor somewhat to his senses, but he’s crossed a line he can’t come back from and never returns to his former self. Leaving this version of the Doctor to run riot was sure to end in more heartbreak.

The Tenth Doctor Had To Regenerate Because He’d Left Himself No Other Options

It was time for Matt Smith’s Eleventh Doctor to take over

This sinister shift in the Doctor’s attitude was a notable symptom of being left to his own devices, but he had already decided he would never travel with a companion after losing Donna Noble (Catherine Tate). Ten was a man of his word, as all iterations of the Doctor are, so it would have been uncharacteristic for him to start leaning on a full-time companion again to be his conscience. Therefore, although he limped through saving the world one more time with Bernard Cribbins’ Wilfred Mott by his side, it was definitely time for him to regenerate and start anew.

Even in some of Ten’s final moments, his slide into selfishness was evident. Rather than diving headfirst into sacrificing himself to save Wilfred from death-by-radiation, the Doctor goes on a passionate rant about how he’s so much more important than Cribbins’ character. It’s heartbreaking to see Ten acting in such a self-centered way, and speaking so coldly about someone he would have once risked his life to rescue without question. This scene serves as the final piece of evidence that Ten had overstayed his welcome, as confirmed by the line, “I’ve lived too long.”

Tennant’s Return As The Fourteenth Doctor Saved Him By Giving Him His Best Friend Back

Donna’s memories returning were the only way Tennant’s Doctor could have been saved

Although he looks slightly different, the Fourteenth Doctor is just Tennant’s iteration coming back for a second round. Still plagued by the same loneliness that haunted him at the end of his Tenth regeneration, Fourteen unconsciously seizes control of the process and essentially restores a once-gone Doctor. Perhaps kept going by the memories of the companions his predecessors had traveled with, Fourteen is able to keep it together long enough to seek out Donna and restore the memories he was compelled to wipe from her mind at the end of Doctor Who season 4.

Donna later theorizes that Ten coming back as Fourteen was because the Doctor was tired, and in need of a long rest, which is why he chose the face Donna would recognize upon his return to Earth. While not confirmed, the show quietly teases that this is indeed the case. So, after centuries of suppressing the feeling, Fourteen is finally able to retire for a while and live with the Nobles. Thankfully, the introduction of Ncuti Gatwa’s Fifteenth Doctor via Doctor Who‘s shocking bi-generation twist meant the universe wasn’t left short of its biggest defender.