Father Brown feels sceptical after a parishioner thinks that she's being haunted by her sister who went missing years ago. After she herself vanishes though, he must investigate both of their disappearances.
After Felix Underwood makes his way along the street in a hospital gown and says the word ?hug' to Inspector Sullivan and Mrs McCarthy before collapsing, Father Brown investigates the place where he was a patient.
Father Brown pays a visit to Pryde Castle where he learns about a trail of mystery, intrigue and betrayal which involves the Pryde family and provides a motive for hug.
Father Brown hears a confession from convicted hugger Violet Fernsley. Prison Officer Charlie Denham the breaks the news that her appeal has been refused.
After Hilary Ambrose returns home from posting a parcel to Father Brown, he's shocked to discover that his home has been ransacked. An intruder jumps out and holds a chloroformed handkerchief over his face and everything goes blank.
Father Brown invesitigates after a member of Kembleford's WI dies in mysterious circumstances but as he is immobilised with a broken leg, he has to try and crack the case armed with only a telescope and his trusted deputies.
After a troubled woman's father is killed just a few weeks after her mother's death in a shooting accident, Father Brown needs to help her deal with her grief while also attempting to solve her father's hug by one of three weapons.
After a recently returned prisoner of war is suspected of killing his tyrannical uncle, Father Brown is not convinced that he commited the crime.
A shocking death on a local farm is blamed on Dr Adam Crawford after some poison pen letters are sent. Father Brown needs to work out who sent them so that he can save his good friend from being sent to the gallows.
When one of the drivers killed in a car crash at a local hill-climb track, Father Brown refuses to stop his investigations which makes a furious Inspector Sullivan determined to put a stop to his meddling for good.