The Fearless Four—Riz, Anvita, Tiana, and Palash—are ready for a well-deserved break after their previous terrifying case involving demonic toys. Their destination? Funmania, the grand amusement park on Bongo Island, which is home to the world's biggest rollercoaster: Big Loopy.
But from the moment they arrive, the island seems . . . odd. The Wailing Witch's eerie cries echo through the night while the island's inhabitants watch them from the shadows, guarding secrets darker than the four friends can imagine. And then, the unthinkable happens.
Their friend, Cyrus, vanishes. One moment, he's strapped into Big Loopy. The next, his seat is empty. No trace. No explanation.
With time running out, the Fearless Four must unravel the island's blood-curdling mysteries before Cyrus is lost forever . . . or before they become the next ones to disappear.