The "Knife Ending"
This ending is on the same path as the Safe ending. Pick one of the following paths through the doors: 4-7-6, 5-7-6 or 4-8-6. This will ensure that the final lock is closed on that path and send you to the Knife ending.
The "Axe Ending"
This ending is on the same path for the True ending. If you've already seen the True ending, this one will require you to backtrack a bit. Open the path map and choose the Operating Room escape, then choose the option for "Before the Door". Go through the dialog until you've been given the dialog choice with clover, and choose "...Told Clover they needed to leave." This will close the final lock on that path and send you on the road to the Axe ending.
Unanswered questions
- Who is the "Captain", and who killed him?