When amateur diver Marcelo Rosales hears the story of a British warship that sank in 1770 near his tiny home town in Patagonia, his youthful curiosity is piqued. It's probably just another rumour, but it can't hurt to find out a little more ... or can it? He begins researching the history of the wreck and making exploratory dives with two of his friends in the murky waters of the Deseado inlet. But then a brutal murder turns the search into a dangerous race to find a secret that has been hidden beneath the sea for more than two centuries.