Their mate or yours
解杀还杀: the opponent stands one move from mate, every passive defense loses, and the only reply is a mate of your own — delivered first. Black's rook on f1 threatens ...Rf0#: the g2 knight seals e1, the d2 soldier seals d1, and the rook itself would seal the rest. Running fails, blocking fails. Red's own mate begins with a jump.