In the latest diary of middle-schooler Greg Heffley, he records his attempts to spend his summer vacation sensibly indoors playing video games and watching television, despite his mother's other ideas.

When Hank the Cowdog hears reports that coyotes are planning to go after the chickens, he manages to resist the temptation to join them and instead thwarts their attack, earning Sally May's forgiveness, and persuading Loper to stop feeding him Cheapo brand dog food.

"When an enemy spy (in a chicken suit!) sneaks on the ranch, it's going to be a wild day for Hank. Will Hank be able to protect the ranch and some newfound valuables of his? But Hank's biggest challenge will be whether he (and Drover) can lead a rescue to save Slim from his ride on a runaway windmill"--Container insert.