The phone buzzed. On it was one new message, consisting of a single word:

Cat?

In the years they had known each other, a ritual had evolved. Whenever either of them felt down, they would mosey over to the other for some gratuitous cat petting and change of scenery. Nothing much happened during these sessions, other than the taking of comfort in not being alone. The cats, by now more used to it than to anything else in the world, merely purred and accepted the elevated levels of affection.

She answered with the customary affirmative response:

Potassium