The fact is that the criminal takes care of the big and important factors.

It's only the little ones he may overlook.

To go back to your friend the Bat, it's because of his skill in little things that he's still at large." "Then you don't think there's a chance that the money from the Union Bank is in this house ?" persisted Miss Cornelia.
"I think it very unlikely." Miss Cornelia put her knitting away and rose.

She still clung tenaciously to her own theories but her belief in them had been badly shaken.
"If you'll come with me, I'll show you to your room," she said a little stiffly.

The detective stepped back to let her pass.
"Sorry to spoil your little theory," he said, and followed her to the door.