"Weird," Sam says, frowning. "I wonder what could cause something like that? Least this way I know Higgs wasn't just messin' with me." Points for Higgs being truthful. He leaves it at that, though, because that's not really a conversation to be having right now. "Do you mean you don't remember her at all?"

Sam isn't really here to solve mysteries, but it sounds like something bizarre is happening involving the train.