"Mayakovsky would find a way to teleport here and slit my throat if I couldn't remember these," Janet says dryly. "Okay, you've got four tiers: Major, Minor, Tertiary, and Quaternary. They all have exceptions. Major Circumstances are pretty basic -- time of day, temperature, what direction you're facing. Minor get a little more nitty-gritty. Dew point, shit like that. The five Tertiary Circumstances are altitude, age, lunar phase, the nearest body of water, and the position of the Pleiades. You can imagine how much that one fucked with me when I got here."