Although at this point I still think that there is some kind of combination lock on the Gate - it's not about an individual door, it's about a specific combination of doors, opening in sequence, that gets you to the Gate.
Maybe you have to spell out "Sacrifice Forgotten" with open doors.
"That's not right, that's not even wrong."
"This is not an idea to be tossed aside lightly, it should be thrown with great force."