18th Emergency (Hardcover, Bound for Schools & Libraries ed.)

Mouse Fawley has just done something very, very dumb. No kid in his right mind would go out of his way to enrage Marv Hammerman, the school bully - but when Mouse saw the picture of the Neanderthal man, he just had to write Marv's name under it. Too bad Marv was standing right behind him while he was doing it. Now Mouse has to choose between being on the run and being killed by the school bully.