Two aspirant nuns stay out too late one night and come back to find the doors to their convent closed and locked.

The first nun immediately begins to worry that their absence will be noticed and they'll get into trouble.

"Don't worry!" says the second nun, "I know another way in."

So the two nuns go round the back of the convent, and the second nun boosts the first onto the back wall.

As the first nun reaches down to help the second up, she says, "You know, I feel like a commando."

"Me too!" grunts the second nun, "But where are we going to find one at this time of night!"