AU. Travelling alone following Grace's death and the rejection from Ryan, Graham and Yaz, the recently regenerated Thirteenth Doctor has recovered her TARDIS and travels to the British Rocket Group, where an alien ship carrying an old enemy has landed bringing a threat that is spreading in the Galaxy.

In a different universe, the Doctor's trial went differently. Now the Doctor has to cope with a new body, even a new gender. As if that isn't bad enough, she has to deal with the questions from rocket scientist Professor Bernard Quatermass, someone known to her. But an old enemy is about to make an appearance...

Shaken from the events of the Pit and worried about the future of his Rocket Group, the last thing Professor Bernhard Quatermass expected was to be shown the future by a stranger with a police box that was bigger on the inside. (Sympathy for the Devil universe)

(NOT a self-insert) Two scientists. One is a renegade time-travelling alien. The other, a man who has fought to reach the stars against enemies from space and on Earth. In the aftermath of the Global Chemicals fiasco, the Doctor and his friend Professor Bernard Quatermass have a talk...