It was an unusually warm night, and so nearly all the doors were left open when the folks went to bed. Freddie was so worked up over his success as a gardener he could not go to sleep.
At last he dozed off, but presently he awoke with a start. What was that strange sound ringing in his ears? He sat up and listened.
Yes, somebody must surely be playing the piano. But what funny music! It seemed to come in funny runs and curious thumps. He called out sharply, and his mother came at once to his side.
"I heard piano-playing," said Freddie, and Mrs. Bobbsey started, for she remembered how Flossie had once told her the same thing.
"Oh, Freddie, are you sure?" she asked.
"Sure," repeated the little fellow. "But it wasn't very good playing."
Mrs. Bobbsey called Uncle Daniel, and the latter lit a lamp and went below into the parlor. Nobody was at the piano or in the room.
"I've made a careful examination," he said, on coming back. "I can see nothing unusual. Some of the children left a piece of cake on the keys of the piano, that's all."
"Well, cake can't play," put in Freddie. "Maybe it was a ghost."
"No, you must have been dreaming," said his mother. "Come, go to sleep," and presently Freddie dropped off. Mrs. Bobbsey was much worried, and the next day the older folks talked the matter over; but nothing came of it.