Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Be7/6. Re1/6...b5/7. Bb3/7...O-O/8. c3/8...d5/9. exd5/9...Nxd5/10. Nxe5/10...Nxe5/11. Rxe5/11...c6/12. d4/12...Bd6/13. Re1/13...Qh4/14. g3/14...Qh3/15. Re4

The surprising 15...g5! is the only move. Black prevents Rh4 by direct means. White can't simply reply with Bxg5 because ...Qf5 would fork the two loose White pieces.