Due to the posts of confusion, I'll try to explain Suicide Chess to the best of my ability.
I'm assuming in Suicide Chess, capturing is obligatory (however, the turn player can choose the piece he wishes to take) and victory is obtained after losing every piece. In this variation the king or bishop can be captured. However:
1. Qxe7 Bf3
loses for White. Therefore:
must be made. Black also has to be careful, since Kd7, Kd6, and Ke6 draws to Qc6 for the first two and Qd5 for the last two. That leaves 5 moves for Black.
We shall see why 1. ... Kd8 also draws here. This may be easier if you have a chessboard where you can move the pieces yourself.
1. ...... Kd8
Ke7 and Ke8 draws to Qf8. Kc7 and Kd7 draws to Qd6. That leaves:
2. ..... Kc8
3. Qg6 Kb8
4. Qf6 Ka8
Kb7 and Kb8 draws to Qc8. Ka7 draws to Qa6. White draws.
Back from the original position, that leaves 4 moves for Black.
Well, I can't figure out quickly why the other 4 moves don't work, but I hope you get the gist of Suicide Chess. Also, SwissGambit's first response is pretty much correct, a king cannot go past a diagonal without capturing the Queen if the diagonal was there before the King was near it.