It was a stormy night. A traveller reached an inn. As the hour was very late, he found the door locked from within. He knocked at the door.
The gate-keeper responded to the knock, saying, "I have lost the key and the door cannot be opened unless you have a silver key with you."
The traveller understood what he meant by the silver key. He immediately slipped a silver coin through the hole, and the door opened.
As soon as he got in, he said to the gate keeper, "I have left my box outside, please bring it." As the gate-keeper went out to bring the box, the traveller closed the door behind him.
The keeper asked him to open the door so that he may come in. Now the traveller replied from within, "I have lost the key and a silver key is needed to open the door." Soon the coin was pushed again through the hole and the dishonest man was let in.
Dishonesty meets dishonesty.