This is one where it just doesn't work to read it as an adult, because everything is so very unbelievable. The idea that they'd just lock up a department store with two small children lost inside it and that emergency operators would dismiss calls as hoaxes the moment they heard a child's voice at the other end of the line was just too ridiculous for this adult reader—not to mention dangerous, as it's basically telling kids not to bother calling 911 if they need help. The thief trapping stuff is basically Home Alone set in a department store, and I can imagine young readers enjoying this part.