Nikki Zenas, Eden Fane, and Wack Leone have barely begun their senior year when Mr. Trout, their beloved computer teacher, is found in the swamp... with poisonous bite marks covering his dead body. Soon a second bite-ridden corpse surfaces. And this time, it's a Ridgeton High classmate named Jon. With the help of their science teacher, who is Mr. Trout's ex-girlfriend, Nikki and Eden learn that the lethal bites might have been made by a certain breed of spider. Then Wack is contacted by a mysterious "Ms. Muffet," who refuses to reveal her true identity until "the time is right." And Nikki starts receiving notes signed by "Mr. Trout," along with spooky valentines. When Wack disappears, Nikki and Eden know they're close to finding the killer. But will they be in time to save Wack from a deadly fate?