After a permanent injury to his leg, Carlton Marsh leaves his federal position to work security for his former boss's new company. His first assignment is protecting paranoid author and illustrator Mara Shore, pen-name for Leah Beach. When the threat becomes real, he will do his best to keep her safe from costumed and masked people who are trying to find the location of the mule she modeled one of her characters after. The cane he walks with becomes an asset to use for her protection. At a Comic-Con the criminals approach her and threaten Leah for information about a mule that her rescue ranch acquired. Sylvester the mule was malnourished and in poor health when he came to her. He is still having some health issues requiring veterinarian care. She refuses to give them what they want, thinking they should be reported to cruelty to animals for the condition he arrived in. She recently added his picture to the comic strip she creates for each weekday. Sylvester is an Appaloosa mule with easily recognizable spots. When Carlton sees the drawing of the mule with spots, he makes an unhappy connection to the recent past. During the last federal case Carlton worked, the same spotted mule ran him over, reinjuring an old wound and ending his hopes of ever walking without a cane and possibly ever having children of his own. He is angry his boss assigned him to the case involving the same animal.

Leah isn't sure she can trust her bodyguard, especially since he acted like the threats weren't serious enough to warrant his help at first. Her past makes it difficult to trust others, especially men. As a teen, a boyfriend who wanted her celebrity father to pay a ransom kidnapped her. That led to a solitary lifestyle, hiding from fame, her father, and people in general. Her love of mules is all she's needed up until now. She's made an exception with a small crew of people who help her at the ranch. With the popularity of her new graphic novel, her agent talked Leah into going on a book tour. Leah had resisted at first, but when a donor cut support to the rescue ranch, she made the decision to promote her book in order to provide continued support for her animals. When she is threatened, all she wants to do is end the tour and go home. A confrontation at her hotel will convince her that Carlton can provide protection to complete the remaining book signing. When they decide to investigate the reason behind the threats, danger will fill their path as they criminals track them to the ranch where her workers and animals are threatened. Once again, Leah will have to deal with betrayal and kidnapping. With Carlton at her side, will she be able to overcome her past fears?