Ancient Egypt and detective stories inspire a similar feverish obsession, and Arthur Phillips, in his new novel "The Egyptologist," has a pretty good idea why. The novel, disguised as a collection of letters and journal entries, traces two stories, each woven from a mix of fact and fabrication, by two very different men.

The first, Ralph Trilipush, describes his determined search, in late 1922, for the tomb of an Egyptian king who supposedly reigned at the very end of the Middle Kingdom (around 1650 B.C.), a surreptitious quest pursued not far from the Valley of the Kings, where Howard Carter is making his famous excavation of the tomb of Tutankhamun. The second story is written 32 years later by Harold Ferrell, a retired private detective, who believes that Trilipush is possibly a fraud and probably the murderer of two men. (Interspersed with Trilipush's journal and Ferrell's account are letters from a Boston woman, Trilipush's fiancée, who Ferrell also once loved.)

Phillips' first novel, "Prague," was a quicksilver concoction tracing the inner lives of a handful of young Americans in the newly opened Eastern Europe of the early 1990s. Their painfully funny efforts to seize an authentic sense of self from the grab bag of secondhand images, styles and ideologies of the late 20th century made it one of those books you either love or hate, depending on how culture-saturated you are and how exquisitely developed your sense of irony is. "The Egyptologist" isn't as fresh or as witty, but it may be more accessible to the kind of reader who found the characters in "Prague" unbearably affected. It's an adventure in unreliable narration, and replete with old-fashioned charms.

Trilipush and Ferrell, who have more in common than either suspects, nonetheless represent two entirely different ways of spinning a story from a handful of fragmented facts. Trilipush is the romantic, having seized upon a papyrus of contested origin as the work of Atum-hadu, a king whose existence most other Egyptologists doubt. That the text consists of some pretty racy poems referring to "the rigid scepter of his power" and "her Nile delta," among other indelicacies, doesn't help his reputation much. One critic has called him "a wishful thinker, a dreamer of unspeakable dreams, a distraction to scholars, and a corrupter of amateurs." Bent on proving himself, he has set off to find Atum-hadu's tomb, funded by his fiancée's wealthy father. According to Trilipush, the facts must be approached boldly, with creativity: "When it comes to incomplete history, one needs to encircle the truth, not bound at it like an amorous kangaroo." (That comparison being a dig at the Australian Ferrell.)

Where Trilipush is eager to jump to the most grandiose conclusions (he's drafted the acknowledgements, epigraph and author bio for his account of the expedition even before he gets to the site), Ferrell is a cynic. He's forever explaining that human beings and their motivations can be boiled down to a small number of sordid categories, all of which he's encountered during his decades in the gumshoe trade, you can bet. "When you understand them, people can't surprise you, you see," he writes with a world-weary authority.

Both men are utterly wrong, Trilipush because he has too much imagination and Ferrell because he has too little. The veritable cathedrals of vanity that Trilipush constructs in his journals (alternately fantasizing about hanging out with Carter at Cairo's Explorer's Club and belittling him as "the passing generation, reluctantly yielding us the torch") are funny, but Ferrell is the shrewder creation. His is the hard-bitten, down-to-earth, private dick's voice we associate with the unvarnished truth, but his simple formula for what drives people -- "money, hunger, lust, power, survival. That's all there is" -- doesn't account for Trilipush's behavior at all.

To the reader goes the diverting task of sifting through the lies, delusions, evasions and misperceptions of these two men to arrive at some notion of what really happened. That makes "The Egyptologist" a kind of puzzle, but most astute thriller and mystery buffs will have figured out the plot's secrets and twists early on. The real game lies in the slow revelation of why neither man can allow himself to understand the truth and how what we need to believe about the world often becomes more important to us than our own lives.

Our next pick: A sister a little too obsessed with her tortured-artist brother, and a teenage girl's mysterious death in the tropics