[FEN "2r2rk1/5p2/p6p/1pP2Pp1/1Q4R1/2P1Pq1P/P4P1K/5R2 b -"]

27... Qxf5 28. a4


w b wb bw | w b wb bw

b     an
    


27...Qxf5      an
    


28. a4      an