Anji is miserable. The Doctor has finally dropped her back in her own time, but all she feels is lonely. Dave is dead, her work bores her, and the last she saw of the Doctor, they were having a fight about his decision to let Fitz go to his certain death in the Siberian wastes of a century ago. An offer to go and work on a time-research project at the Naryskin Institute in Siberia seems to offer a change, and possibly a connection with her lost past, but the mission turns out not to have the purpose Anji had thought. While Anji battles against the freezing cold, and other, less palpable forces, the Doctor is involved with the Grand Duchess Anastasia, a showman billed as the Great Attractor, and his mysterious servant Holiday, as he tries to work out why all of them are so desperate to be involved with the Naryshkin project, and just what did happen to Fitz's Siberian expedition a hundred years ago...