Actually, "Checkmate" is there (at least when I look). It's the one
titled "Cookie - Checkmate." In other words, it started out as a
cookie and then spawned more stories.

Chronological order of the stories, as best I can figure, is as follows:
* Checkmate
* Keeper's Snitch
* Natural Magic
* The Come and Go Room (except that it's AU)
* Earthly Pleasures
* The Kissing Bough

This is also the order they were composed (except The Come and Go
Room), so you can follow the stories along to see how a smidgen of an
idea becomes a universe, becomes a story arc, becomes... well, who
knows what it will become? Except that we hope it will keep on for
quite a while.