Five children and their nurse teleport from a derelict hospital to a beautiful meadow. This is brief and engaging read that does almost nothing I expected--it's effectively a science fantasy take on the portal fantasy trope, and the entire plot is a gentle mystery: what's the nature of the world the children are leaving, and the world they're entering, and how did they get there? It's successfully paced against the struggle to survive in a new place; I would have loved the cozy, perilous, mysterious atmosphere as a kid, but as an adult reader it feels a little sketched-in, particularly the ending.

Reader beware re: the depiction of disability. I personally dislike mystery illnesses as a trope, but it suits the general vibe. The children are

Spoiler

partially cured of their conditions

in the portal world, which is handled with relatively delicacy but still is what it is.