They always say "When you're at work, leave your problems at the door." The problem with that is that Lily's problem IS her job. And this also isn't a job where you get mandatory breaks and sick leave... Lily is dead. She has been for several thousand years. And working as a Death isn't very fun at all. It gets incredibly annoying dealing with the troubled souls of wary wanderers, lost adventurers and the plain unlucky.

After a particularly stressful day, she finally snaps and just about does the unthinkable. Thankfully, her higher-up intervenes, telling the young Death that she's being reassigned to a different universal plane: The magical land of Equestria. Her higher-up informs her that it's "better for everyone", and sends her on her way. There was just ONE little detail she wasn't informed of...

No-one ever actually dies in Equestria.