I had hoped for something about halfway between (1) a book intended to describe the behavior of subatomic particles to general readers and (2) one for those with considerable background in quantum physics. But to me it seemed that “Through Two Doors At Once” is aimed at an audience very much closer to (2) than to (1) — so much so that much of the book was either incomprehensible to me or delved into distinctions relevant only to specialists.