Once upon a time, there was a brilliant criminal.
One caught the other in a trap and killed them.
The detective, before dying, told his nemesis that his trap was too complicated. That there was a simpler trap that he could have used. His nemesis agreed.
"The next time I kill you," he replied, "I promise you the labyrinth that consists of a single straight line that is invisible and endless."
He stepped back a few steps. Then, very carefully, he fired.