He’s big in Italy. Ditto England, Germany, and Spain. But Massachusetts-based thriller author Glenn Cooper is still largely unknown, and notably under-published, in the one place you’d least expect: his home country of America.

There are plenty of American authors who don’t sell in Europe, and even more European authors who don’t sell in America. Occasionally, there are midlist American authors who find big audiences in certain overseas markets. (Paul Auster’s a bestseller here, for example, yet is more akin to a rock star than a writer in France.) But there are very few authors, especially American ones, who are huge in Europe and barely published in the States. Such is the case with Cooper.

A doctor-turned biomedical executive-turned author, Cooper had an unexpected European sensation with his first book, 2009’s Library of the Dead. Then represented by agent Steve Kasdan (who now works at Amazon but was then at the Sandra Dykstra Agency), the book was bought in a flurry of international deals and wound up becoming the number one translated title in Italy where, according to Cooper’s current agent, Simon Lipskar at Writers House, it has sold over 400,000 copies.

Library, Lipskar said, went on to hit the bestsellers lists in both England and Germany but, didn’t spark much interest in the U.S. As Lipskar recounts, although the book ignited “staggering” deals in Europe in 2008—it drew seven figures in some places and was sold in a total of 30 foreign markets—it was universally passed-on in the U.S. After HarperCollins Canada acquired Library, it urged its U.S. counterpart to publish the novel. HarperCollins acquiesced but didn’t put much muscle behind the book, releasing it in 2009 as a paperback original under the new name, Secret of the Seventh Son.

Lipskar, who took on Cooper for his third book—Cooper’s second book, a sequel to his debut called Book of Souls was also published in the U.S. by HC again to lackluster sales—is now trying to rectify his author’s curious publishing record in America as he bolsters his author’s booming stature in Europe. Lipskar has been closing foreign deals on Cooper’s latest two books, both standalone thrillers, The Tenth Chamber and The Devil Will Come. In Spain, where Lipskar said Library of the Dead has sold nearly 200,000 copies, Lipskar sold the two new titles for six figures each to Random House Mondadori.

So what about the States? Lipskar said he’s waiting for the right offer to publish Cooper here, this time the proper way. “It should be a no-brainer that an author of commercial fiction who’s found a million readers across the world, and writes about America, should be read with the same enthusiasm in his home market.”