The Spy Who Clutched A Playing Card

Published in Ellery Queen Mystery Magazine, 02/1968.
"On a frozen waste near the Gulf of Finland an agent from the private intelligence organization known as SPAD was performing one of the most audacious acts conceivable in the world of espionage . . . a fascinating jigsaw puzzle—but Rand, the Double-C man, thought there were too many pieces to fit together."