The Memory Thief (Paperback)
Twin brother and sister Benji and Kelly wander off at the local county fair after witnessing their parents argue. When Benji runs into a group of bullies, he escapes into a tent called The Memory Emporium, where he meets a strange old man inside named Louis. The old man shows him a magically vivid memory of a fighter pilot, in the hopes of getting Benji to pay to see other memories Louis has collected from people over the years.
Benji quickly realizes the ability to take memories could help his parents stop fighting with each other, and he asks Louis to teach him how to become a "memory thief." But Louis isn't the only person with the ability to show and manipulate memories. There's also the mysterious Genevieve, a Memory Thief with much more nefarious motives.
Benji learns how to manipulate memories himself, but having that power comes at a cost to his family, and possibly to his own mind as well. Genevieve's powers get out of control as she steals more and more memories from people in town--including Benji's sister, Kelly. Benji must learn to use this newfound power, as he is the only one able to stop Genevieve.