Brave and dashing adventurer Sir Lionel Frost considers himself to be the world's foremost investigator of myths and monsters. The trouble is, no one else seems to agree. He sees a chance to prove himself by travelling to America's Pacific Northwest to discover the world's most legendary creature: The Missing Link. What Sir Lionel discovers isn't a terrifying remnant of Man's primitive ancestry but Mr Link, a slightly silly, surprisingly smart, and soulful beast. As species go, he's as endangered as they get. He's possibly the last of his kind, he's lonely, and he believes that Sir Lionel is the one man alive who can help him. Along with the independent and resourceful Adelina Fortnight, who possesses the only known map to the fabled valley of Shangri-La, the unlikely trio embarks on a riotous roller-coaster ride of a journey to find Link's distant relatives.