What is the line here? A game I just played at chess.com, in the analysis, it was a missed win at a point. My mind is saturated right now, and I can't think of the line. Can you help me out?
The obvious tactic is 

1) ... a6 2) Na3 Nxd4 3) cxN Qxd4 4) QxQ BxQ and you are forking the two rooks on a1 and g1

Disclaimer: I haven't checked this with an engine but it would be my first thought during the game. The engine may find a hole in this