BOOK REVIEW : Speculation Ladled On With a Heavy Hand : THE SIGN AND THE SEAL; A Quest for the Lost Ark of the Covenant, <i> by Graham Hancock</i> , Crown $22; 608 pages

According to an ancient tradition, the holy city of Axum in Ethiopia is the last resting place of the Ark of the Covenant, the golden chest in which Moses placed the stone tablets on which God had inscribed the Ten Commandments.

When English journalist Graham Hancock first heard the story from an Ethiopian monk, he was suitably skeptical.

“Are you telling me,” he asked, “that this legend is literally true?”

“It is not a legend,” the mysterious “guardian monk” answered. “It is history.”

Legend or history? That’s precisely the question that Hancock sets out to answer in “The Sign and the Seal,” a breathless first-person account of his quest after the Ark of the Covenant.

It’s part travelogue, part true-adventure, part mystery-thriller. But mostly it’s a whacking big dose of amateur scholarship alloyed with a fervid imagination and the kind of narrative that comes in handy when telling ghost stories around a campfire.

“The gift of an ancient and secret science,” he writes of the Ark. “I think of it as a key to the sealed and unremembered history of our species, a sign of our forgotten glory, and a testament to lost truths about ourselves.”

Hancock, a former correspondent for the Economist, was at work on one of the more curious coffee-table books in publishing history: a puff piece on Ethiopia under the Mengistu regime, which was best known for sending death squads to shoot miscellaneous enemies of the state and charging the victims’ families for the bullets.

“I was under no illusions,” he confesses. “They would not have footed the bills, or permitted me to visit historic sites forbidden to others, if they did not think that what I was doing would be helpful to them.”

At large in Ethiopia, Hancock began to pick up the threads of myth and magic that have attached themselves to the Ark of the Covenant over several millennia.

Mindful of the wealth of legend and lore of the Ark--and the pop-culture currency of “Raiders of the Lost Ark”--Hancock set out to discover the true origin, nature and destiny of the Ark.

Along the way, he tutored himself on various fringe theories that link the Ark with the arcane numerological wisdom of the ancient Hebrews, the Knights Templar, Wolfram’s “Parsival,” the cathedral at Chartres, Freemasonry, the iconography of the Virgin Mary, the legend of the Holy Grail, the mythic Asiatic monarch known as Prester John, the search for the source of the Nile, the Ethiopian Jews once called “Falashas,” and various other odds and ends of history-as-conspiracy.

Hancock anticipates and rejects those critics “with a pedantic and cavilling attitude toward history” who might balk at some of his more daring leaps of faith and imagination.

“Sceptical and pragmatic by nature,” Hancock writes of himself, he came to the conclusion that “academics did not have all the answers”--and he gave himself permission to engage in “a highly speculative thesis” on the “beguiling pattern of coincidences” that he detected in the historical record.

“It’s speculation that we are indulging in here,” he admits, “and there is room for a little imaginative license.”

“The Sign and the Seal” is entertaining precisely because it’s so trippy, but Hancock ladles so much weirdness and wackiness into his bubbling caldron of a book, so much speculation and surmise, that the reader’s mind begins to boggle.

Still, Hancock urges us on: “Pursuing the Ark through Ethiopia,” he writes, “was something like pursuing a ghost through maze”--and the author thereby neatly sums up the reader’s experience of his own book.

Next: Richard Eder reviews “Ever After” by Graham Swift (Knopf).