Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7/9...Bd7/10. Bxd7/10...Qxd7/11. Qh5/11...g6/12. Qe5

Black doesn't want the g8-knight to be hanging after a potential Qxh8, so 12...Kf7 is played to guard it. Black is planning to trap the queen in the corner with ...Nf6, so ...Ne7 would be a big mistake.