Until this moment, Alec hasn't actually considered the possibility that there were entirely separate planets. He's quite certain he's not on his own anymore, but more? He's staring at the ground, momentarily stunned.

It makes sense, now that he considers it. But the technology required to travel to another planet? Through space? He can't begin to fathom it.

"How many have you been to?" Alec asks. "Planets, I mean?"