There's a storm brewing over Eerie-on-Sea, and the fisherfolk say a monster is the cause. Someone has woken the ancient Gargantis, who sleeps in the watery caves beneath this spooky seaside town where legends have a habit of coming to life. It seems the Gargantis is looking for something: a treasure stolen from her underwater lair. And it just might be in the Lost-and-Foundery at the Grand Nautilus Hotel, in the care of one Herbert Lemon, Lost-and-Founder....

"Herbie Lemon, Lost-and-Founder at the Grand Nautilus Hotel, and his fearless friend Violet Parma have unearthed many secrets in their village of Eerie-on-Sea: secrets lurking beneath the waves, lapping onto the beaches, and lying behind locked doors. When their brilliant and ruthless nemesis, Sebastian Eels, returns with a plan to open the long-shuttered waxworks museum, Herbie and Violet suspect nefarious motives. Their investigation leads them...