Team Unexplainers attempt to become the first dry humans to prove the existence of the wet and elusive Mermaid. Whilst the UK braces itself for a winter onslaught of hurricane force winds, Mike starts to worry that John's latest water-based quest for the truth will take both of them to Davy Jones' Locker.

A trip to see a local storyteller leaves John believing he's found some 'solid fact' on Mermaids but, as the storm winds build, a visit to the national library of Wales produces the opposite of evidence and leaves John stormy with anger.

With John's Mermaid obsession unrelenting, Mike attempts to wash away the theory with help from a marine biologist. But it backfires spectacularly and The Unexplainers find themselves heading out on the high seas using the magical floating powers of something called "a boat". Show less