Helpmate in 28

This one is for sheer fun, possibly the longest helpmate ever devised.

Newcomers, please recall that in helpmates, Black moves first and is cooperating in finding a single variation in which white may deliver checkmate in the stipulated number of moves. However, neither side may move into check, (or move a pinned piece leaving their king in check, or otherwise make a illegal move). In the final checkmate position, standard rules apply.

Note: it is a bit unusual for Black king to be in check in a position, but it is Black to play first, and neither side may make a illegal move, so the first Black move is forced. The rest is forced by the logic that Black has to navigate the minefield of white pawn controlled squares, while creating a passer to promote to allow White to promote. All of this takes 28 dance steps.