DOCTOR WHO IN DETAIL

When the Thirteenth Doctor crash lands into a train Yaz is one of the police officers who attends the scene. Yaz is an school friend of Ryan and, after helping the newly regenerated Thirteenth Doctor, she was accidentally sucked into space and joined the Doctor after her rescue.

Yaz develops feelings towards the Doctor but they are not reciprocated, and the Doctor leaves Yaz in Sheffield as she handles her regeneration alone.

First regular appearance: The Woman Who Fell to Earth

Final regular appearance: The Power of the Doctor