There is a cat named Bob. You must choose to either kill him or save him, but you cannot actually kill him.
Example:
Bob was sitting at the river and a strong current suddenly swept him away (kill)
The current carried Bob to a branch hanging over the river and he grabbed onto it (save)
I'll go first.
A big fish swam up to where Bob was hanging and bit him on the tail (kill)
But before he got down from the tree, it fell over with Bob in it (kill)