Ava realises too late that her hand has brushed the rail.
"Don't touch that!" Her mother snaps. "Other people have touched it."
Ava waits with her palms facing the sky and they shake in time with her sobs, while her mother springs a pump head of sanitiser from her handbag.
At home, Ava strips. Boils her clothes and her blankets, vacuums, swabs her bedroom with bleach-soaked paper towels, scrubs herself with steel wool and soap, and shuts her bedroom door.
"You're a good sensible girl," her mother hisses through the keyhole. Her pursed lips mist over as Ava seals the door with stretches of cling film.
"You'll be safe at least. I'll ride the train, I'll buy thin-sliced cheese." Her mother's telephone voice pierces the layers between them.
Ava holds her palm out, scanning for any draught on which particles of other people might insinuate themselves. There are none.
Her mother leans closer, one palm flat against the door. "I'll probably die of bacteria out here", she ventures, and waits.
But Ava doesn't say anything, because all the words have already been used by somebody else. Instead, she stands in the middle of the room with her palms facing the sky. This time she doesn't cry. Her mother speaks again but Ava won't hear anything, because that's like holding something secondhand inside you. And Ava won't think anything, in case other people have already thought it.
First published online in North & South Magazine in 2017.