Mystery of the Empty House — Dorothy Martin

“Look!” cries Pat. “There's a light in the empty house!”
“Impossible,” says Barbara. “That place has been deserted for ages.”

But there was a light…moving past the darkened windows. Someone -- or something -- is prowling there in the dead of night!

“Come one,” whispers Barbara. “We're going to find out what's going on -- before it's too late!