Puzzle 9482

Sorry, me again. Why doesn't the black queen move to A5 after Rc4? I saw the rook move, but it seemed that Qa5 refuted.

Qa5 looks sensible since the black queen could move to c7 later.

But Qa5?? Nd6+! Kd8 (only move) Nxb7+ forking king and queen, and white wins the queen for free.

In the puzzle continuation, black at least gets some material.

p.s.
Adding the weblink makes life much easier for your readers.

http://en.lichess.org/training/9482