After telling the story of Flint’s last journey to young Jim Hawkins, Billy Bones has a heart attack and dies just as Jim and his friends are attacked by pirates. The gang escapes into the town where they hire out a boat and crew to find the hidden treasure, which was revealed by Bones before he died. On their voyage across the seas, they soon find out that not everyone on board can be trusted.

Dr. Dempsey is an American scientist who has become a skeptic. He isn’t enthusiastic to be sent by his employer to Scotland to (dis)prove the existence of the Loch Ness monster. He finds the locals stubborn, ‘primitive’ and all but hospitable, not in the least because the Nessie legend is the only tourist attraction. He still gets romantically attracted by his independent inn-keeper Laura, and both her kid and his local assistant end up making him face a small family of Nessie-dinosaurs, but is this to be made public?