Found the most understandable way I could of expressing the desire to return an array of points, composing a path between two Cartesian points, where the path is traversed in a two-part orthogonal/diagonal optimal distance manner (which first based on a parameter), halting early when a populated cache is found. This after several attempts. I don’t think I am the best at expressing mathematical ideas. Fortunately math, in a sense, is not the only component of the game.
Route ranking complete, I added a new filter function to pick the final point and applied it to the letter quest! Added data for the second quest NPC, some basic state logic, and I have a working quest! If the letter gets destroyed, the quest is put into a fail state.
Removed a lot of useless getters and setters. Not the .js way.