138. a piece already in the way, by the chariot

Helpmates in xiangqi

4 moves

Black moves first and both sides cooperate: Black, Red, Black, Red, and Red's second move mates. Black has 29 legal first moves and exactly one of them works. 18 pieces, Black 49 to Red 20 in material, mate by the chariot. Themes: a piece already in the way, a quiet first move by…