In a race against time, the gang have to rescue Robbo from Ragnar's evil clutches. But can the Sea Born trap Ragnar in the coral for good, and save Paradise Island? Still believing that Robbo is the Sea Born, Ragnar captures him and is determined to claim his body, leaving Robbo trapped in the coral forever. When Chloe discovers Robbo tied up at the whirlpool, she makes a deal with Ragnar. If she brings the real Sea Born to him, Ragnar must grant her life, just as he always promised. Convinced by Chloe that she has a plan to rescue Robbo, Abi and Megan concentrate on protecting Peter's coral sealing device from the greatest cat burglar ghost ever, Grant Carey. Ragnar has sent him to steal the device and stop the coral being sealed while he's still in there. The girls mount a daring heist to try and outwit Grant Carey and Chloe and Tai approach Ragnar's whirlpool to save Robbo. With the clock ticking, it's a nail-biting race against time as Tai has to defeat Ragnar and save his best friend and the island. It's time for Chloe to decide whose side she's really on.