It's winter, and all is well with the tribe. Their new magic, an ability to make portals from one place to another, which was found by one of their members during the early-summer trip to meet with the other tribes in the area, let them both build up a decadent food stockpile and move to a much deeper part of the cave system without the worry of being unable to find their way back out. No-one has had to go hungry, and even the fiercest ice storm doesn't reach them; they are as content as kobolds can be.

Well, aside from their new mage, that is. She's bored, and curious. Making portals to known places is straightforward enough, with the magic she found, but that's far from the limit of what it can do... so one day, she slips away, portals off to a different cave system - one can't be too careful, after all - and experiments.

Temperature roughly the same... gravity roughly the same... air the same, not into stone or underwater or in a volcano or on top of a mountain... but, instead of patterning it after a place she knows, what happens if she only specifies those things, and lets the innate patterns of the spot she's casting on do the rest? Particularly this one part, which seems to specify the world...

She finishes the spell, and hesitates for just a moment before activating it.