A young man (Robbie) gets into an altercation on the ferry from Aberdeen to Shetland, witnessed by a young woman (Leanne). The two spend time together, but when Leanne wakes as the ferry arrives in Shetland, Robbie has disappeared. Later that day, a little boy ends up in intensive care after eating a ‘sweet’ he found on the beach. D.I. Jimmy Perez searches the beach that night and recovers a rucksack, but not before a hooded figure tries, and fails, to take it from him.
Back at the station, Perez and his team (D.S Alison ‘Tosh’ McIntosh and D.C. Sandy Wilson) discover that the bag contains multiple packets of brightly coloured pills and the pulpy remains of a boarding pass belonging to someone called Robert. Perez needs to speak to Leanne again.