Nate Dray, Chess Problem Painting, "Sam Lloyd, 1897 - Orange moves first, mates in two"

"Sam Lloyd, 1897 - Orange moves first, mates in two"

The chess problem.

Typically, in a chess problem presentation, white moves first and achieves mate in a specified number of moves.

Here orange takes the place of white and moves first. 

There is only one correct solution, i.e. one series of moves, and only one, that results in mate in the specified number of moves.

Here's a hint for this problem; the move orange must make is seemingly innocuous. It doesn't threaten a new piece or open a new line of attack on any one piece.