Alan Lightman is a genius. No, really, he is. He taught astrophysics for dozens of years at Harvard and is now an adjunct professor of humanities at M.I.T. He has authored several books on science, as well as four previous novels, including his first, “Einstein’s Dreams,” a wonderful story of non-traditional concepts of time. The man is all about science. So, perhaps, with the beginning of his seventh decade not far off, and having spent his life surrounded by things that can be explained scientifically, Lightman is expressing a personal interest with “Ghost,” the story of a seemingly logical, science-minded man who sees … something.

David Kurzweil is a humble man, living a modest life in a rooming house. After being let go from his lengthy tenure at a bank, David takes a job working at a mortuary as a runner—a person who retrieves death certificates from doctors and hospitals so that funerals can legally occur. David likes his job and the people he works with. But, one night, not long after he starts working there, David witnesses something he can’t explain.

The book opens with David explaining how unsettled he is. He feels nauseated; he isn’t sleeping or eating. He thinks he’s crazy, but he isn’t crazy, is he? Lightman deftly captures the thoughts of a man who needs an explanation for what he saw. Until now, David has always fancied himself reasonable and unflappable.

“And I don’t think I’m at all … how should I put it … suggestible. I believe that’s the word. Never in my life have I been suggestible. At a party years ago, a hypnotist tried to put me under and failed. He said I was not “suggestible,” and then he looked at me as if I were a man unable to fall in love. If I could travel back to that party years ago—I think I was in my mid-twenties—I would tell that guy and everyone else that I am happy not being suggestible. I prefer seeing the world as it is.”

After perfectly expressing David’s fear and panic, Lightman shifts the narration to the third person, interweaving past and present. We learn of David’s failed first marriage to Bethany, and his new relationship with the lovely Ellen. Martin, David’s boss, is perhaps the most wonderful character in the book. Martin is the fourth-generation owner of the funeral home—a delicate, elderly gentleman who has panic attacks when faced with the possibility of having to leave the building, needing to be calmed by his sweet wife, Jenny. Lightman does a great job of describing Martin, giving readers the sense that they, too, are handling him with kid gloves.

Eventually, David confides his vision to Ellen, who tries to be supportive. But, her apparent lack of belief in what he saw leaves David feeling empty. He then shares his story with his landlord, which turns out to be a big mistake. Word of David’s sighting spreads and, soon, a reporter from the town newspaper calls to talk to about what he has seen. David is not happy about the unwanted attention, and Martin is angry that the funeral home is now a center of interest for townspeople—scientists and loonies, alike. But, David is also torn between his need to understand what he saw and his wish that it had never happened. As more and more people turn up wishing to speak with him, run tests on him or just be near him, he gives in to the pressure and allows himself to be studied.

Lightman’s writing can best be described as gentle. With his careful storytelling, readers get the sense that he is fascinated by the idea that there are some things science can’t explain. He eases the reader into David’s life and does an amazing job of making David’s experiences and reactions seem like the most normal occurrences. He makes David’s unusual sighting feel much less important than what happens around him as a result. When what David saw is actually revealed late in the book, it barely registers after everything else that has taken place. With “Ghost,” it’s Lightman himself who does the real haunting.