When Mr. Haney, the principal, asks Arthur to bring home a mysterious brown envelope marked "private" and "confidential," Arthur can’t help but wonder what’s inside. His friends Buster, Francine and Muffy all take guesses: what if it’s a note about a failing grade? Or a lost library book? Or --- terror of all terrors --- a letter saying Arthur has to attend summer school!

By the time he arrives home from school Arthur is racked with worry. He figures bad news won’t be so bad if his mother never reads it, so he doesn’t tell her when he sees the envelope accidentally fall into the waste basket. Arthur finally learns a gentle lesson about telling the truth and facing his fears, but you'll have to find out for yourself what was in the mysterious brown envelope.