Firstly, there is a great duel between the bishop and the knight, in which the bishop's long-range power proves too strong.

After the bishop v knight battle seems to be over on move 56 with the knight gone, leaving bishop and one pawn against two pawns, there is another twist in the story. If black plays the obvious 58....Kxa2, the 'b' pawn runs away and eventually the bishop will have to either capture or blockade it, allowing white to play Kg6, grabbing the last black pawn and leading to a draw.

So the black king has to retrace its steps all the way back, working with the bishop to try and contain white's rolling 'a' and 'b' pawns, while holding onto the black 'g' pawn.