"I was gonna ask, if you got the postcard," Clark says, with a tone that seems to fill in the end of that with an unpronounced but I didn't want to be weird. "It's a good aquarium. I liked it a lot."

The reviews are in. What to say next? Do you like aquariums? What is your favourite aquatic creature? Your top three, if you had to pick? Probably an improvement on the other things Clark could ask, things that are more sharply curious than what Rick happens to think of sharks, for all their teeth.

Or maybe not just ask, but something more instructive. Call your dad, the world's ending.

"It's going to be kind of a base of operations," he says, instead.