Portal - Wall Grafitti 3

The last wall in the decorated room.
I also decided to write out the words from the walls: (from top left)

Because I could not stop for death
He kindly stopped for me
The cube had food and
_____ ammo
find immortality.

Why x18 ??????????

Not in cruelty,
Not in wrath,
The reaper came today;
An angel visited
this gray path,
and took the cube away.

(If you notice any mistakes or think you know what the missing word is let me know!)

Wall 1 [link]
Wall 2 [link]

The cake is a LIE.