Doorbells are mysteriously ringing all over the neighborhood. The four private eyes are in for some surprises -- like burning cakes, overflowing bathtubs and a phone that doesn't ring -- on the invisible ringer's trail. But the culprit turns out to be the biggest surprise of...
Wizard, Tubby, Skinny, and Snitch match their wits against the invisible door ringer. 'Full of excitement and suspense.' --Independent Schools Junior Booklist. Children's Books of the Year 1966 (CSA)