Prologue
In a dream, the fisherman Peter Grimes relives the recent inquest held into the death of his young apprentice. The coroner has cast an open verdict, leaving the town speculating and gossiping. Ellen Orford, the school mistress, arrives and lulls Peter into a calmer sleep.

Act I
Scene 1
Grimes returns from fishing and the townspeople, still full of rumours after the trial, refuse to help him bring in his boat. Only the retired sea captain Balstrode and Ned Keene, the local ‘chemist’, are willing to give a hand. Keene tells Grimes that he has arranged for a new apprentice to come and work for him. When asked to collect the boy, Hobson – the carter – refuses, but consents when Ellen offers to accompany the boy on the journey. A powerful storm threatens, during which Balstrode suggests to Grimes that he should leave the town or marry Ellen and change his solitary ways. Grimes rejects his advice, declaring ‘I am native, rooted here,’ and that he will only marry Ellen when he has enough money to earn the respect of the Borough.

Scene 2
With the storm raging outside, the townsfolk are sheltering in the local pub. To the annoyance of Auntie – the landlady – Mrs Sedley, a widow addicted to laudanum, arrives to wait for Ned Keene, her supplier. Auntie’s ‘nieces’ are teasing the inebriated Methodist fisherman Bob Boles, when Ned Keene arrives with the news that part of the cliff has collapsed by Grime’s hut. To the astonishment of the onlookers Grimes bursts in – as wild as the storm – distracted and disoriented. When a fight threatens to break out between him and Boles, Balstrode calls for a song to calm the atmosphere. The song is interrupted by the arrival of Hobson, Ellen and the new apprentice, soaked to the skin and exhausted from their journey. Instead of allowing him to rest, Grimes insists on taking the boy straight home and carries him out into the night.

Act II
Scene 1
It is Sunday and Ellen has decided not to go to church, but to question the silent apprentice about his life. While trying to encourage the boy to speak, she notices that his clothing is torn and that he has a bruise on his neck. Grimes arrives and orders the boy to go fishing. Ellen intervenes, reminding him that the apprentice is entitled to a day of rest. He loses his temper, pushing Ellen to the ground and running off with the boy. When the locals emerge from church, Bob Boles, who has witnessed this incident, stirs the Borough into action against Grimes. Allowed to vent their anger, the townsmen resolve to set out for his hut to get to the truth – ‘with the branding iron and knife’. They leave Ellen, Auntie and the two Nieces alone on the beach, reflecting on their role and relationship to the men in the Borough.

Scene 2
Grimes and the apprentice prepare for the fishing trip. Peter is very distracted, fearing that his dream of marrying Ellen is now crushed. When he hears the men from the Borough approaching, he panics and hurries the boy down the steep ladder to the beach. With the knock on the door he hears the boy scream, and fearing an accident, scrambles quickly after him. Reverend Adams, Mayor Swallow, Keene and Balstrode enter the hut and are surprised by its orderly state, but neither Grimes nor the boy are there.

Act III
Grimes finds the dead apprentice at the base of the cliff.

Scene 1
The annual Borough dance is in full swing. Auntie’s ‘nieces’ are teasing the lawyer Swallow, who, like everyone else, is extremely drunk. Mrs Sedley, re-imagining herself as the local sleuth, tries to convince Ned Keene that Grimes has killed his apprentice. A few days have passed, with no sign of him or the boy. Balstrode arrives with Ellen, who has discovered the boy’s jumper on the tide line. Balstrode tells Ellen that he has seen Grimes’s boat, and together they commit to finding him before the mob do. When they have gone, Mrs Sedley, who has overheard their conversation, incites the Borough to action and the manhunt for Grimes begins.