The detectives look into the discovery of a gold Viking hoard stolen from a prehistoric burial chamber. After the site is reopened, they unearth a series of secrets and betrayals leading to a thousand-year-old cover-up. 

At an exclusive wine tasting, host Raymond Bettane dies from a spiked drink. As the detectives question each of the guests, Mick makes a shocking discovery about Bettane's vintage wines.