"The Rosetta Key" a heart-pounding historical adventure

Instead of reheating their 1980s Indiana Jones formula in the imminent sequel, Steven Spielberg and George Lucas should've made a movie about a newer, smarter swashbuckler involved with a lost ark: Ethan Gage. Seattle Times reporter William Dietrich's 18th-century adventure hero was last glimpsed in his 2007 novel "Napoleon's Pyramids," mixed up in Bonaparte's excellent Egyptian adventure and a near-fatal ballooning mishap high above the Nile.

But you can't kill a guy whose adventures sell big in 24 languages and countries. Faster than a boulder bound for Indy's skull, Ethan Gage bounces back in "The Rosetta Key," (Harper, 339 pp., $25.95) an utterly captivating romp from the treacherous tunnels beneath Jerusalem to the lost City of Ghosts (Petra, Jordan) to the tumult of revolutionary Paris.

The Gage series is marketed as a Da Vinci Code-like thriller, because its plot is driven by Gage's hunt for the Book of Thoth, an enchanting scroll Moses stole from the Great Pyramid and took to Israel, linking the sages and mages of antiquity with secret societies that make civilization their personal puppet show.

"Was there a secret history that wound through all the world's time, paralleling the commonly known one?" Gage muses. "Were all the faiths, myths, and stories an endless interweaving and embroidery of ancient texts, wisdom built on wisdom, and mystery concealed by yet more mystery?"

Well, duh! Dietrich spins a merry magical mystery tour, winningly intricate and anchored to actual historical figures and events. And yet the mystery isn't really the key to the story's charm. Sure, you want to find out what the secret code revealed by the Rosetta Stone spells out in terms of superpowers and the fate of humanity.

But it's the history that grabs you, rewritten as a pulse-pounding cliffhanger action flick. See Gage pursued by firing squads and sabers, Arab warriors defending the Dome of the Rock and a log-sized crocodile! Cast into an underwater cave and a pit of vipers! Menaced by the pasha Dzezzar the Butcher, and Big Ned the hulking British sailor, and his old landlady, who claims he owes her back rent!

As bullets whizz past his scalp, Gage passes on all manner of wonderful arcana about the real world. Dietrich is a Pulitzer-winning reporter, and he's done homework about everything from Napoleon's gratuitously gory 1799 siege of the Holy Land to the fate of the Roman temple devoted to the Egyptian goddess Isis (it became Paris' Notre Dame Cathedral).

When Gage needs a new rifle with spirals carved into its barrel and a spyglass for a sight so he can hit a tack at 200 yards, you get enough detail on its forging to feel you could make one for yourself in a pinch. And of course, it's a muzzle-loader that takes long, tension-building seconds to pack with gunpowder, giving bad guys time to take aim with lesser weapons.

Gage is like MacGyver with more interesting fixes to get out of, and cooler materials to work with. He's reminiscent of Mark Twain's Connecticut Yankee in King Arthur's court, only he comes by his technical wizardry without benefit of time travel. Gage is an old crony of Ben Franklin, who he's forever quoting, and he wows crowds via bold electrical experiments that would do Ben proud.

Dietrich's novelistic virtues are also his vices. He describes scenes in gorgeously observed detail, often nicely phrased, but he packs in so much research the narrative sometimes reminds me of Clive James' comment that the young Arnold Schwarzenegger's pumped-up body resembled "a condom stuffed with walnuts." Often characters sound like they're reading a reporter's notes aloud.

But they're great notes, and great characters. Mr. Spielberg! Mr. Lucas! It's your move.

Tim Appelo is associate editor of City Arts Magazine.