The fifth season of the BBC's award-winning crime-drama series, Shetland, comes it's thrilling climax this week with time running out for Perez's team to crack the case and find Zezi before tragedy strikes again. Douglas Henshall takes on the role of DI Jimmy Perez once again this week alongside Alison O'Donnell's DS Alison "Tosh" McIntosh and Steven Robertson's DS Sandy Wilson. Rakie Ayola returns as grieving mother Olivia, presumably for the final time, while Mark Bonnar's guilt-ridden drunkard Duncan and Catherine Walker's Alice also feature. Perez and his team struggle to keep an increasingly agitated Olivia under control as they step up their investigation and close in on Zezi's whereabouts. But after making a terrible discovery on a local beach and realising they've been betrayed by one of their own, the team finds the odds stacked against them in a race against time which threatens to shake the entire island. Piecing the case together, Perez closes in on Zezi's location, but can he reach her before it's too late? Shetland - Tuesday 9:00pm on BBC One.