Sherlock Bones's home, the Natural History Museum, has added an exciting new exhibit, Reef to Shore, that includes a mangrove forest and shallow coral reef habitat, with touch tanks in between. When Sherlock overhears a that a swamp monster has been sighted, he gathers his team to investigate. At first Sherlock Bones suspects Nivlac, a quirky octopus with a talent for camouflage--and tank pranks.

But then, loud bellowing leads Bones and team to the mangroves, where they find a horrifying long-haired green beast! Can they escape the creature--or is it too late for our beloved frogmouth bird skeleton and his ragtag mystery-solving team?