Imagine someone who you've come to trust and admire, to confide in and lean on, because you and she have shared an unimaginable horror. 

Imagine the relationship grows and deepens over years, as you both rise from the ashes and grief, and discover meaning in the abyss. 

Someone once described September 11, 2001, as the day that never ends.  I accompanied my wife to a 20th anniversary of her graduation from Villanova last weekend, and at one point collapsed on a park bench with my youngest, after playing catch on the sunny field near the "Oreo." 

The plaque on the bench gave birth and death dates for a Christopher Duffy, died September 11, 2001, age 23.  I googled using my cell phone. He had been a lacrosse captain in high school, and graduated Villanova in 2000. Chris had died on the 89th floor of the south tower. 

Eleven floors below him, in the same insane inferno, Tania, waiting near an elevator bank, was crushed by flying, burning debris, her arm nearly severed. She would undoubtedly have died inside the tower, had not a mysterious man in a red bandana led her to safety, before returning to help others. 

Tania's fiancee, Dave, in the north tower, already was dead, though Tania wouldn't learn this until later.  Through the dull, numbing days, weeks, and months that followed, Tania struggled to find meaning, a reason to go on.  Finally, over several years, she found a support group in the 9/11 survivors. Over time she became a leading spokesperson. 

In what I've mentioned so far, Christopher Duffy is very real. So is Dave, and so is the man in the red bandana, who lost his life that day saving others.  But the climax of the book is in the title of this true story.  If that is not clear, the subtitle is, "The True Story of an Incredible Deception."

It is  a gripping read, in part because it brings back in technicolor descriptions the details of a time of unparalleled national shock and grief.  And in part because at each turn of the page, the deception continues.

It is a fascinating exploration of human nature. In the wake of meeting someone who is not what they appear to be, we are faced with two questions, which grind equally. How could we not have known? And how could they lie so convincingly? 

Well crafted and suspenseful, even with the conclusion obvious, the book suggests a truly neurotic mind. But that really explains nothing.  Except, perhaps, how little we really understand the people who surround us.