The Sixth Doctor has regenerated, having sacrificed his fifth persona to save Peri’s life. But things are not going well …

On this occasion the process of regeneration is by no means smooth, for the even-tempered, good-humoured fifth Doctor has given way to a rather disturbed and unsettled successor.

In a particularly irascible moment the new Doctor comes dangerously close to committing a shocking crime. Overwhelmed with guilt for his violent behaviour, the repentant Time Lord decides to become a hermit …