十二生肖We're transported back to the tropical island of Saint Marie, and this time with a new Detective Inspector in place - but will DI Mervin Wilson remain in the job for long? Following the recently cracked case of ‘who shot the Santas?’, along with the revelation that his estranged mother has passed away, Mervin is ready to get back home and leave the island for good. But when a case close to the hearts of those at the station presents itself, is he tempted to extend his stay?　　As Mervin continues to ruffle feathers, the police team pull together to solve some of the island’s most confounding cases yet.