Cast of The Young Poisoner's Handbook

Hugh O'Conor portrays Graham Young, the young poisoner who becomes obsessed with toxic substances and their effects on people.

Antony Sher plays Dr. Ernest Zeigler, a psychiatrist who tries to understand and treat Graham's disturbing behavior.

Ruth Sheen appears as Molly, a character entangled in Graham's dark world of poison and manipulation.

Roger Lloyd Pack takes on the role of Fred, a figure impacted by Graham's dangerous experiments with toxins.

Charlotte Coleman portrays Winnie, a person affected by the twisted actions of Graham in the film.

Paul Stacey plays Dennis, a character caught up in the chaos created by Graham's deadly interests.

John Thomson appears as Nathan, a part of the story influenced by Graham's unsettling choices.

Jack Deam takes on the role of Mick, a character impacted by the consequences of Graham's toxic experiments.

Charlie Creed-Miles portrays Berridge, a figure affected by the events surrounding Graham's dangerous obsessions.

Robert Demeger appears as Mr. Dexter, a character entangled in the disturbing world of poison crafted by Graham.

Tobias Arnold plays Young Graham, offering insight into the early years of the infamous poisoner.

Norman Caro appears as Mr. Goez, a character impacted by the unfolding events involving Graham's deadly experiments.