In Ghosts of Christmas Past, set in the December of 1912, Dorian Gray returns to London where his portrait is stolen and held to ransom. In order to get it back, he is blackmailed into committing a terrible murder. And the only man who can help him is the man he has to kill: Sherlock Holmes.

Joining Alexander Vlahos in this festive edition are Nicholas Briggs as Holmes (reprising his role from the popular series of Big Finish Sherlock Holmes audio dramas) and Rupert Young as James Moriarty, better known to Merlin fans as Sir Leon. Featuring alongside them are Rebecca Newman as Sibyl Vane, Richard Nichols as Alan Campbell with Seán Carlsen, Wilf Scolding, Lorna Rose Harris, Sophie Melville and Alex Griffin-Griffiths.

Don't forget that you can catch up with the five-part Confessions series for just £12.99, and you can see Alexander Vlahos in the epic Merlin finale this Christmas (Saturday 22nd December and Christmas Eve), as well as his new BBC One drama series Privates, starting in January.