Sire's Hollow is a quaint little town not too far from Ponyville. Anon would never have any reason to set foot in the place were it not for his best friend, Sunburst, asking him for a massive solid:

Keep his mother, Stellar Flare, preoccupied for a few days while he conducts research on the town's recently discovered magical properties.

Sunburst loves his mom, and they've worked through their communication issues before, but as head of the Sire's Hollow Development Committee, she would never approve of the tests he intends to run. So, Anon will act as a "distraction," allowing Sunburst to get done before she notices.

He does a better job than either of them were expecting.