Picking up from where things were left at the end of series one, master puzzle-setter John ‘Ludwig' Taylor is now a Crime Scene Consultant working on ‘impossible' crimes for the Cambridge Police Authority. No longer having to masquerade as his brother, he's openly more ‘Ludwig' than ever - brilliant at solving puzzles but hopeless at everything else.

But John's identical twin brother, James, is still missing, and now that he's an official employee of the station, John is forbidden from using any police resources to look for his brother or uncover exactly what he was investigating.

Of course, John won't stop and neither will Lucy, John's sister-in-law and wife of his missing brother James - a puzzle needs solving and a husband and father needs bringing home. One masquerade may have ended, but a new one has just begun.