To a casual visitor, the island of Heavenly Daze is just like a dozen others off the coast of Maine. It is decorated with graceful Victorian mansions, carpeted with gray cobblestones and bright wild flowers, and populated by sturdy, hard-working folks-most of whom are unaware that the island of Heavenly Daze is not just like the other islands of coastal Maine. The small town that crowns its peak consists of seven buildings, each inhabited, according to divine decree, by an angel who has been commanded to guard and help anyone who crosses the threshold.

Unexpected hijinks and...