Siberian Trap-Sicilian Defence

on the moves that have the round brackets () just click on them and press play

Assuming that moves 1 through 8 happened, why would white capture. 10. Nxd4? 

So the white queen can capture the knight.... I'm sure

in this scenario white queen didn't have a change to capture...

I agree with Aarongo. If it twas me. Id g3 it up....js. this didn't make much sense.

After Nh3, g3, force Ng4 to retreat or f2 and be cap'd. And if d4 goes to f3 id take him with my queen...the Ng4 can do whatever and be dealt with accordingly.

White isn't losing after 8..Ng4. He can play g3.

White is not losing yet after Ng4. It is only after h3?? that the trap is sprung and white has to give up his queen for two minor pieces to stop mate