8
7
6
5
4
3
2
1
	a	b	c	d	e	f	g	h

INTRODUCTION

This is an example of a conventional (What-happens-next?) chess puzzle.
I'm showing it to help illustrate the difference between everyday chess
puzzles and Raymond Smullyan's brilliant 'Retrograde' puzzles.

So why not give it a try before clicking SOLUTION or CONTINUE?

WHITE TO PLAY AND RUIN BLACK'S DAY

Black resigned immediately after White's next move.  What was it?

(HINT: Knight takes Rook is obvious, but there's a much better move available.)