In this audacious historical novel, an American spy agrees to help the victors divide up the spoils of World War I by literally drawing the new borders of the Middle East—only to discover that the relic he holds has far greater power than he could have imagined.

In 1917, Elias Winters arrives in Egypt with a mysterious key entrusted to him by an old-boy network of Western power brokers. He is tasked to use the key to draw the new negotiated border in Ottoman Palestine. But he soon discovers he serves a different mission for the “Old Ones”—an ancient society known for their extraordinary longevity, strength, and ability to draw power from the land.

Elias is determined to harness the key's powers to become one of the Old Ones himself. However, he is not alone in his quest to shape the region in the aftermath of war. Dr. Minna Weizmann believes the key can transform Ottoman Palestine into a Jewish homeland, while Dawood al-Haddad, a young Muslim university student hired to assist Elias, senses the key's dark potential for the Arab nationalist cause.

Competing against others drawn to the key’s mysterious power, Elias, Minna, and Dawood find themselves in a race to finish the line and seize control of history itself. In a region on the verge of transformation and upheaval, The Invisible Line captures a moment of historic turmoil and the lengths we’ll go in the pursuit of power.