Landon Murphy never imagined he would spend his summer battling the animated trash monster known as the Megalajunk, and he is eager to continue studying from the wizard-like janitors at the School of Garbage. He'll need to improve his skills with magical pushbrooms and plungers now that the Thingamajunks have gone rogue.

When two Thingamajunks show up at Landon's mother's wedding, Landon is desperate to save his family. Using the lock he kept after defeating the Megalajunk, Landon accidentally triggers his own temporary transformation into the trash leviathan.

Now, he and his stepsister, Jade Shu, must team up again with Sabra, Dr. Bernard Weizmann, and Daisy Gates to figure out why the Thingamajunks are popping up to ruin parties, weddings, concerts, and other celebrations. Landon suspects the Locksmith is behind the attacks, but information about the mysterious figure is scarce.

The questions continue to pile up, but one thing is certain: War is coming to the landfill, and Landon, Jade, and Sabra will need all their courage, creativity, and focus to lay a trap for the Thingamajunks--before it's too late.