Back in the swinging '60s, Neil Brewer and Virginia McClain were lovers. Four decades on, Neil is recovering from a heart attack and his thoughts return to Virginia, now the senior bacteriologist at R&P Labs. He suggests a romantic reunion but Virginia turns him down, only to find when Neil is murdered that he has left a substantial legacy to the lab. But there's a catch; to receive it, they must first solve a series of clues. So the scientific quintet reluctantly embark on their treasure hunt and try to track down Neil's killer, as Ellis fends off the attentions of an amorous chocolatier, Mitch becomes a bodyguard and Rob discovers an unexpected talent for breaking and entering.