Some would say this doesn't have a happy ending, but to someone who has gone thru the same and much worse this is indeed a happy ending, seeing the intern killing all of them and getting away with it, that felt good not great but good, she didn't go thru that much, but still she was mistreated and they didn't respect her and got another intern, so she can't be blamed for what she did even if it's wrong.
Over the last 6 years of working I have gone thru the same things, I didn't even stand up for myself at the beginning and was used and took advantage of cause they thought I can't stand up for my self, till i had enough of it and I faced them and then they started respecting me and knew my worth, but I'd always leave the place after a year or so cause I don't like to become as filthy as they are or in her case become a murderer ?