“I hope he’s not a salesman, I thought; then he smiled as I stepped into the lobby, a real smile, and I liked him instantly and relaxed. No, I told myself, he’s not selling anything, and I couldn’t have been more wrong about that.”

Si’s reaction to meeting Rube conveys information in a quick and enlightening way. It conveys Rube’s physical appearance and overall bearing as friendly and charming but also intense and perhaps even pushy. It also highlights Si’s sense of humor, and it contains a touch of foreshadowing as Si informs the reader that he is wrong when he says Rube isn’t selling anything.

“To see how you react when the impossible is happening: some people can’t take it. They rely on things being what they ought to be, and behaving as they always have. When suddenly they aren’t, and don’t, their senses actually surrender, can’t cope. Right at that desk, they fail. Don, downstairs, was one; we had to give him a pill even after he knew what had happened. But you’re guided from within, not from the outside. You know what you know.”

After Si passes the first test, he is confused and asks Rossoff what the point of it was. Rossoff’s explanation is an insightful comment on Si’s character and the first clue as to why they believe Si is perfect for the project. It is also an interesting take on human nature in terms of the way people respond to things they cannot understand or explain.

“Picture one of those upper apartments standing empty for two months in the summer of 1894. As it did. Picture our arranging—as we are—to sublet that very apartment for those identical months during the coming summer. And now understand me. If Albert Einstein is right once again—and he is— then hard as it may be to comprehend, the summer of 1894 still exists. That silent empty apartment exists back in that summer precisely as it exists in the summer that is coming. Unaltered and unchanged, identical in each, and existing in each. I believe it may be possible this summer, just barely possible, you understand, for a man to walk out of that unchanged apartment and into that other summer.”

The passage contains Danziger’s explanation of Einstein’s theories and his own addendum regarding the possibilities of time travel. It is thorough and scientifically accurate if somewhat simplified. It also encapsulates one of the most popular time travel tropes in literature. The whole experiment Si undertakes is built upon this image in this quote.