Wait, white played g4! They pushed their g2 pawn to g4. And there's an en passant target on g3. Let me check the FEN: "5r2/pp3r1k/7p/2p5/6P1/8/q7/7K b - - 0 28" en_passant: "g3" - so en passant is available on g3. The board shows rank 4: ". . . . . . P . 4" - white pawn on g4 (position 7 from left = g4). So white played g2-g4. And the en passant square is g3. Now material is -22 (I'm up 22!). White has only king + pawn now. Looking at the board: - White: K h1, pawn g4 (just moved from g2) - Black: K h7, Q a2, R f8, R f7, pawns a7, b7, c5, h6 Wait, where's my c-pawn? The FEN shows c5. And what about the rook? F7 has rook, f8 has rook. Looking at the legal moves, I notice Rf1#! That's checkmate! Let me verify: Rf1 from f7 to f1. - Rook on f1 attacks king on h1 (same rank). Check! - King on h1: - Move: g1 (attacked by rook), g2 (empty, attacked by rook? f1 to g2 not on line. But wait, g2 is on diagonal from h1. Let me check what attacks g2. My queen on a2 attacks g2? a2 to g2 same rank, with b2, c2, d2, e2, f2 between. Wait, are those empty? Let me check. b2 captured (pawn gone). c2 empty. d2-e2 empty. f2 empty. So queen on a2 attacks g2! Yes! So g2 attacked. - h2 (empty, attacked by queen on a2? a2 to h2 same rank, no pieces between. Yes attacked!) - h1 attacked by rook on f1. - So all king moves attacked. And rook can't be captured (no white piece attacks f1). - Mate! Wait, but I need to verify the rook path. Rf1: rook on f7 to f1. f-file: f6, f5, f4, f3, f2, f1. All empty? Let me check. - f6 empty - f5 empty - f4 empty - f3 empty - f2 empty - f1 empty Yes, all empty. So Rf1 is legal. And it's checkmate! Let me play Rf1#!