The series is the first to star Peter Capaldi as the twelfth incarnation of the Doctor, an alien Time Lord who travels through time and space in his TARDIS, which appears to be a British police box on the outside. It also stars Jenna Coleman as his companion, Clara Oswald. Also playing a major recurring role in the series is Samuel Anderson as Danny Pink, Clara's boyfriend. The main story arc revolves around a mysterious woman called Missy (Michelle Gomez), who is often seen welcoming people who have died throughout the series to the "afterlife". Her true identity is later revealed to be the Doctor's arch-enemy, the Master, who has hatched a plan using the help of the Cybermen and through manipulation of the Doctor and Clara's relationship.