Riddle of the Week

An all blue, round, two story house sits on a big blue hill. In it, lives a mother, a father, and a baby, and a servant, maid, gardener, and cook. One day, the mother and father leave for a movie. When they return, the baby is dead in its crib. They interrogate their helpers: the only ones who could have killed the baby.

The maid says she was cleaning the stairs.

The gardener says he was trimming the weeds.

The servants says she was cleaning dust off of windows and corners.

The cook says he was taking a refreshing nap outside on the peaceful hill.

Who killed the baby?

(Answer will be revealed next week. Please post your ideas in comments!)