Miranda woke Saturday morning to the preternatural stillness of snowfall. Marvin was next to her, doing a reasonable impression of a bear-skin rug and purring as though his last life depended on it.

She scratched his ears and ran her hand along his fur. “Good morning, Marvin.”

He flicked his tail by way of response.

“‘Mom, can I please get a cat?’ he said. ‘I’ll do all the work, I swear,’ he said.’” She spoke aloud to cat as much as to the empty house. “Maybe I should drop your litter box off at...