Some people think that museums are boring places full of glass cases, dust and stuff no one cares about: wrong! In a hidden headquarters below the exhibits there's a gang ready to handle dangerous, spooky or just plain weird problems: the Museum Mystery Squad. Techie-genius Nabster, mile-a-minute Kennedy and sharp-eyed Laurie (along with Colin the hamster!) tackle the surprising conundrums happening at the museum. From pre-historic creatures that move and secret Egyptian codes to missing treasure and strange messages from the past, there's no brain-twisting, totally improbable puzzle the Squad can't solve.The discovery of new Viking treasure brings the museum its biggest exhibit yet -- a giant longboat. With such a huge attraction on show there's plenty of room to hide a secret, or two. In the Case of the Vanishing Viking, the Squad investigate legendary longboats, rare runes and hidden hoards to try to solve their latest mystery.