Living in the well-established neighborhood of Moose Street (which could be in Syracuse, N. Y., where Mazer grew up with her author parents), 11-year-old Lena Rosen's activities are typical of the 60's (or the 90's): playing with friends and avoiding enemies while watching her baby sister in the park; feeling friendly toward a classmate despite his bullying brother and abusive home; coping with an art teacher who's unappreciative of her imaginative response to an assignment, and with teasing because she is a ""brain""; being kind, just once, to the class outcast. Through it all, Lena is troubled by prejudice, even from her best friend: ""The trouble with you Jewish people is that you're all brains and no muscles,"" Nancy remarks. ""My mother said so."" Religion is everyone's concern here, and the Rosens are the only Jews. In every chapter, the thoughtless, hurtful words rankle; with a precise ear for dialogue, Mazer poignantly captures the smug, excluding atmosphere--so much so that her deftly sketched characters and incidents fade in comparison. A book with an important message, skillfully delivered.