Let Me Ax You a Question Trophy in Zero Escape: The Nonary Games

The Ax Ending is one of the three bad endings in 999. On the flowchart, it is the right branch of the left path (the same one with the True Ending). It can be unlocked by choosing 5 or 4 / 7 / 1 and failing to meet all the story checkpoints for the True Ending (see Don't Forget Your Towel).

If you've already unlocked the True Ending, you will need to replay a bit for this one – you can't just go to the divergence point and play through as there are no choices to be made at the divergence point.

On the left path, choose the "Operating Room" escape, and choose "Before the Door". This will bring you to the point where Clover is hesitating. Choose "...Told Clover they needed to leave". Running out the rest of the scene will take you back to the flowchart, and you should notice that one of the key icons is now locked (assuming you've already unlocked the True Ending, which you should have if you've been following the Roadmap).

Now you will want to move to "Outside the Room" on the bottom left path (the divergence point of the Coffin/True Endings) and let it play out to unlock this trophy.