M030 - Seasons of Fear

The Doctor has a story to tell. Who to and why will be revealed in episodes to come, but for now we hear the story of an immortal man who has made a deal with the devil.

In Shanghai, close to Charley's own time, the two separate so Charley can visit her boyfriend Alex. This is when the Doctor meets a strange man who claims to have killed him. This starts a time-traversing tale where the Doctor and Charley find the strange man in Ancient Rome, pre-Norman England, and in the witty 18th Century as his power for long life stretches towards immortality and his moral view of life diminishes to nothing.

It's a thrilling tale, and very well told. The reveal of who the devils behind it all are is a little underwhelming for anyone not steeped in Whovian lore, but the story wraps up neatly and is followed by a tease of grander mysteries to come.