Kevin is actually celebrating two birthdays: His own--he is turning 13 and becoming an "obnoxious teenager"--and the anniversary of the creation of Freak the Mighty. Kevin aims high in his hopes for the perfect birthday gift. He hopes to fly on the space shuttle, but his mother assures him that this will not happen. He suggests a linear accelerator, "so I can split a few atoms." Since he received an ornithopter the year before, he asks for a helicopter. When Gwen counters with a "jet plane," Kevin likes the idea.
"Cool," Freak says. "A Learjet."
But Freak seems to be perfectly happy with the present he receives: a brand new computer, "the one he's been drooling over in his computer magazines."