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. Qh5

9...g6 is the only safe move to block the check, because:
 * 9...Qg6?? 10.Ne5+ wins the queen directly, and
 * 9...Kd7?? 10.Qf7+ and the queen has to be shipped overboard with 10...Qe7, as either 10...Be7 or 10...Ne7 allow the pretty double check 11.Nb8+ followed by mate on e8.