Rose Tyler is dead.
Donna Noble dead.
River Song is dead.
And now, his beloved Clara Oswlad is dead. And the Doctor is sick of it. The Doctor is sick of losing. He's sick of losing battles. He's sick of losing people. He's sick of losing the games that his enemies make for him. And he's decided that the best way to keep from losing the games is by not playing at all.
After regenerating out of pure sorrow, the new, thirteenth incarnation of the Doctor, going by the childhood name of Theta Sigma, finds a Gallfreyan colony on the distant moon of Ky'Yao. He decides to leave behind the Doctor and his past, and take on a new identity as a professor at the Time Lord Academy. But he didn't expect to meet her.
With only a few years left of being a student, Carillium Twalek of the Patrexian chapterhouse knew everything there was to know about the Doctor. She had read every book, every article, and every archive the was on his existence in time. So when Theta Sigma joins he academy, somehow she feels as if it's the doctor in disguise, despite his refusal.
Her older brother, Eriyus, who was in the Arcalian chapterhouse and was kicked out of the Academey a few years before for his final test, insists that she gives up on him and focus in keeping her position as top in her class. But she can't help but wonder. And Carillium refuses to quit.