Connie Willis has a reputation for writing intelligent and intricate science fiction, and Passage not only upholds that reputation, it elevates it. More like a medical thriller than a futuristic novel centered around a science fiction technology such as time travel, Passage is rich with multiple layers and believable characters within an intricate and credible plot. Willis's quirky sense of humor is present although perhaps just a bit more controlled and less madcap than some of her other books.

Dr. Joanna Lander is a cognitive psychologist at Mercy Hospital, and the focus of her research is the near-death experience (NDE). She interviews people who have coded and were resuscitated to try to to identify the common elements and to see if she can find out what causes the NDE and the purpose it serves in the dying brain.

Of course, a hospital seems as if it could provide plenty of opportunities for interview subjects, especially since her friend, Vielle, an emergency room nurse, calls her every time a patient codes and revives. But much of the time, her efforts are foiled by Maurice Mandrake, author of a popular book on NDEs. Mandrake asks leading questions of his subjects in order to record an experience that fits into his book's premise that the NDE is a metaphysical experience.

Then Joanna links up with Dr. Richard Wright, who is also studying NDEs, using a drug that simulates the near-death experience. When their volunteer list dwindles and the project is in danger of losing its funding, Joanna goes under the drug herself and embarks on a series of strange journeys as she tries to piece together the clues her experiences provide.

It wouldn't be right to reveal any more of the plot, save to say that it is as complex as the warren that is Mercy General, as complex yet as logical as the functions of the brain. The story makes you think and puzzle and work to understand, and the rich multi-levels of meaning and metaphor burst in your mind in blinding epiphany.

The characters are wonderful as well. Joanna is warm, funny and caring, someone you would like to get to know, and she is supported by a marvelous cast, including the tough and tender Vielle, Maisie, a feisty child with heart disease and a passion for disasters, Richard with his lab coat pockets of endless plenty, and Kit, the fragile-looking but resilient niece of Joanna's high school English teacher.

Not only is Passage Connie Willis's best book thus far, this is one of the best books I've read all year. Don't pass it by.