This chess puzzle involves several fairly common themes, most notably how to build an attack with fewer pieces. At this juncture, things look bad for Black. Black is down a rook, a knight, and a pawn, and Black's king is stranded in the center while White's sleeps snugly behind a wall of pawns and a rook. However, at the end of seven moves, Black is going to checkmate White. How?
Black to move and mate in seven.
Don't cheat!
Solution:
1. ... Bxf2+
2. Rxf2 Qc1+
3. Rf1 Qe3+
4. Kh1 Nf2+
5. Kg1 Nh3++
6. Kh1 Qg1+
7. Rxg1 Nf2#
The FEN is:
7Q/r2pkB1p/p3p2q/1pb1N3/4n3/8/PP3PPP/RN3RK1