Unexpected luck is sometimes bad

Once upon a time, there were two notorious thieves. They were on a lookout for a rich man as their prey. They were very overconfident and consider themselves very clever. 

After finding for 2-3 days for their prey, they finally got one. They entered a rich person’s house and went on finding the safe. They found the safe open and were happy at their unexpected luck. The safe was already open and there was no need to unlock the safe. 

They just piled up everything and were moving out.

 Suddenly, the lights come up and the thieves could the room full of police officers, constables and sub-constables. They had came to arrest the thieves. 

The thieves understood earlier that it was a trap.