Stephen will play a snooker champion named Danny Sloane. He will be in the fourth episode of series two. Photos show him looking focused.

The show stars David Mitchell as a puzzle maker who solves crimes. It also features Anna Maxwell Martin. People liked it and said it was 'gripping'.

The first series was very popular, with 9.5 million viewers.

The show is about John, who pretends to be his twin brother James, a detective. He goes to the police station to find out what happened to James.

Series two continues from where series one ended. David and Anna are back, and new actors join the show.

John is now a consultant for the police. He uses his intelligence to solve 'impossible' crimes. He cannot use police resources to find his twin.

A third series of Ludwig has been confirmed.

David said he is happy to return to the show. He wants to solve more mysteries and has prepared for it.

Series two of Ludwig starts on August 20 at 9pm on BBC One. The first three episodes will be on iPlayer at the same time.