Easy puzzle

What is this suppost to be about cause after u finish puzzle you cant get checkmate. My 2 options for the game is: The first option, Queen takes Bishop, Castle kills horse/knight for check then the Queen or the white Bishop goes to c1 or f1 to defend the king. The second option is, white Bishop takes castle, black bishop takes Queen and the game plays on. So im asking what this puzzle is suppost to be about. If anyone has an idea please share.

Lildoom:

If 3. Bxb8, then 3. - Bxc4 and black wins.

If 3. Qxa6, then 3. - Rxb1+ 4. Qf1 Rxf1 and black wins.

If 3. Qf1, then 3. - Bxf1 4. Kxf1 Rxb1+ and black wins.

Not mate, but black always wins.

really nice, attacking the queen and threatening checkmate with the same move, brilliant!