Lieutenant Alex Easton and kan horse, Hob, are travelling from Gallacia to Ruravia to visit kan twin friends, Madeline and Roderick Usher. Madeline, who is ill, has written to ask Easton to come. Now, Easton stops near a tarn—a small mountain lake—to examine a flesh-like mushroom. Ka suggests that Hob take a drink from the tarn, but the water looks dark and suspicious, and Hob refuses. The Usher’s decrepit house sits on the other side of the tarn.

A woman approaches from behind and warns Easton not to touch the mushroom, which is a stinking redgill, or A. foetida. The woman advises Easton to hold kan horse, and she pokes the mushroom with a stick, prompting it to release a putrid scent. The woman is Eugenia Potter, an illustrator and amateur mycologist, and she is working on documenting a fungus that she has discovered. When she publishes her findings, she will name the fungus A. potteri, and she hopes that the discovery will gain her entrance to the Mycology Society. Gallacian, the language of Easton’s home country, does not have a word for mushrooms, but the language does have seven pronoun variations, including the military-specific ka/kan.