Battlelines are drawn as the Duke and Duchess of Argyll enter into a bloody separation, all played out in the white-hot glare of a ravenous press.

Russian Empress Catherine the Great faces challenges to her throne on all sides, as she meets the forthright and bold Lieutenant Grigory Potemkin.

Soon after his poetry recital, Leonard Quinton is found hanging in the conservatory. When Father Brown realises that he could not have committed suicide, the search begins for a murderer.

Villanelle’s new circumstances are looking bleak, while Eve makes a dangerous deal with an old acquaintance. Villanelle is surprised when she is approached by a figure from her past.

Blackmail threatens the monarchy and Sherlock is about to meet the woman who beats him.

Blackmail threatens the monarchy and Sherlock is about to meet the woman who beats him.