Sixth-grader Mac reveals his secret job by speaking directly to the reader. Mac’s given name is Christian Barrett, but all the students know him as Mac. (One of his customers called Christian “MacGyver” once, and the shortened form stuck.) Mac can fix problems and acquire goods for anyone in need at his elementary school, Grades 1 to 8—for a price. Sometimes the price is cash, sometimes a favor, sometimes a combination. Occasionally Mac also takes on a pro bono case. Those are usually recommended by his best friend and business manager, Vince.

Mac has a desk in the fourth stall from the highest window in the East Wing boys’ room, a part of the school rarely frequented by staff. The toilet was taken out after a supposedly successful prank involving Principal Dickerson’s bathroom use. Jimmy Snickers lined the seat with enough superglue to necessitate the removal of both the principal and the toilet for separation procedures at a nearby hospital. The empty stall fits Mac’s desk and chair and another chair for the prospective client. Mac keeps standard office hours during early recess, lunch, and regular recess; he has an arrangement with the janitor to keep out and keep quiet; he employs Joe, a large, loyal eighth grader to keep students in line (literally) outside the bathroom door.