Black plays and wins in 5 moves https://lichess.org/WidnMOts/black
1... Be3+ 2. Kb1 Bd2 3. Qe6+ Ka3 4. cxb6 Rb3+ 5. Ka1 Bc3#
The analysis board does checkmate in 5 moves
1... Na2+ 2. Kb1 Nc3+ 3. Ka1 Rd2 4. Qg8+ Nd5+ 5. Kb1 Rd1#
Covering the check with the horse while unblocking the bishop to check, nice move!
Source:
This publication is in my collection "500 chess puzzles. Mate in 5. Advanced & Expert Level."