They were all silent for a long, uncomfortable minute. If you ignored Krystle’s grunts.

Jessica looked back to Alex, “What’s a paradox?”

Alex almost laughed incredulously. But, seeing Jessica holding down Krystle, thought better of it, “Didn’t you see Back to the Future?”

Jessica gave him one of her raised brow looks. “Yeah, so?”

“So,” he said, and started pacing, “A paradox, specifically, a temporal paradox, is a situation in which a time traveler causes, through actions in the past, the exclusion of the possibility of the time travel that allowed those actions to be taken.”

“Uh, what?” Amanda, this time.

“For lack of a better explanation, it would be like one of us, coming back today to change our past to make ourself a millionaire in the future,” he sighed in exasperation.

Jessica snorted, “Why didn’t you just say that in the first place?”

Becky had slipped out her phone during the talk to look at the time, “Okay,” she said quietly. “I vote for the memory wiping.”