Arthur's Heart Mix-Up

Arthur's Heart Mix-Up is a book written by Marc Brown first published January 1, 2004.

Summary
Arthur finishes his science fair project just in time for the fair, but an over-excited Pal scatters Arthur's carefully laid out human heart. Arthur is so desperate to fix his broken heart, it's all he can talk about to his friends. Binky, the Brain, Francine, Muffy, and Buster are baffled as to who mystery girl is who has broken Arthur's heart, and head to Arthur's house to cheer him up. Will Arthur's heart be mended—and in time for the science fair?