This is a true tour de force. First, White appears to be mating in two after 1 e7 or 1 Qh6 or 1 g7, but he soon finds that he is the one who is mated after 1...Qa5+ 2 Kxa5 Kb7 with killing threats of promoting or playing ...Nd2. So White plays 1 Qxe5 Qa5+ 2 Kxa5 Kb7 3 Qb2+ Ka7. Now 4 Qxe2? Nd2 still gets White mated, so the only move is a counter-sacrifice, 4 Qb8+ Kxb8 5 Ka6. After 5...e1(Q) 6 g7 Qa5+ 7 Kxa5 Kb7 8 g8(Q) e2, we are back where we started. Another trip on the merry-go-round: 9 Qa8+ Kxa8 10 Ka6 e1(Q) 11 e7. Note that if White had promoted his e-pawn first and now had a pawn on g7, Black would win with ...Qg3. But 6...Qg3 doesn't work after 7 e7!
After 11 e7, one more series of sacrifices: 11...Qa5+ 12 Kxa5 Kb7 13 e8(Q) and Black has run out of Queens. However, 13...Nd2 threatens mate, and the only answer is 14 Qa8+ Kxa8 15 Ka6. Black gets back to stop the f-pawn after 15...Nxc4 (or ...Nf3) 16 f6 Nd6 17 f7 Nxf7, but then 18 a5! and White will be stalemated next move.
The moral is: sometimes having a queen isn't all it's cracked up to be.
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