92. a piece returns where it came from, by the soldier

Helpmates in xiangqi

4 moves

Black moves first and both sides cooperate: Black, Red, Black, Red, and Red's second move mates. Black has 31 legal first moves and exactly one of them works. 18 pieces, Black 46.5 to Red 13 in material, mate by the soldier. Themes: a piece returns where it came from, the general…