The tank’s heater burbled ominously. The first fish, the yellow one, was floating close to the surface.
“What do you think’s wrong?”
The green fish was floating lower but steadier, its fins twitchier but still keeping it level.
“This one doesn’t seem quite right too. You think the heater’s broken?”
“It is making a kind of a sinister noise.”
The fish continued to swim about, the humans beyond them standing stock-still.
“I tell you, they shouldn’t be doing that,” said the yellow fish. “Just standing like that.”
“I know, I know,” the green fish agreed. “Let me turn down the heater and see if the humans get less lethargic.”