A tip-off from an old friend leads Gillian to seek the truth behind the murder of retired English teacher Peter Farquhar.

Accompanied by James, a new acquaintance who seems to harbour secrets about the case, Gillian learns that the victim Peter is far more complex than he was depicted at court.

New information leads Gillian to question the prosecution’s narrative about killer Ben Field. She decides to use literary tools to unlock his motives.

Gillian is surprised to discover that Peter and Ben kept their relationship secret from the other members of the book club, who included Peter’s closest friends.

Peter’s behaviour is worrying his friends. Gillian wonders whether she has discovered the ‘trigger’ for the murder.

Peter is dead. Gillian is shocked by Ben’s next move. Seeking understanding, she delves into his poetry – only to discover an expanding web of deception.

Years after the murder, the police close in on Ben. What they discover overturns Gillian’s understanding of the case.

James finally reveals his secrets, leading Gillian to re-examine a dark episode from her own past.