Once, one of your pawns on files a, b, c, d may step one square diagonally forward onto an empty square. Not a capture.
You draft Servants' Entrance in Buff mode. Passive: it works on its own the whole time you hold it, with nothing to activate.
As a movement card, it changes how one of your pieces is allowed to move.
“The a-through-d staff know which hinges are oiled.”