At the Sound of the Beep
Twins Matthew and Mathilda Greene aren't too surprised when their parents tell them they're getting a divorce-- after all, they're always fighting-- but they're shocked when they hear that Matthew is going with Dad and Mathilda with Mom. When their parents refuse to change this arrangement, the twins run away to stay together. Disguised as two boys, they end op in Golden Gate Park, where they become acquainted with the local homeless people. But when several homeless die mysteriously-- apparently poisoned-- the twins know that they and their new friends are not safe. Can Matthew and Mathilda figure out who the killer is?
This is a pretty suspenseful mystery. It gets a little tense at times, but it's still a lot of fun, and there is a happy ending.