The long-awaited sequel to 2015's Dark Fire: Yesterday's Tears, finds billionaire tech genius Edan Duff and his wife, Jane Garrison, the ex-military pilot and master combatant better known as Sim, repatriated to the United States and back in their cliff side California home. Their return followed a years-long self-imposed exile in Barbados to avoid imprisonment or worse by the ruthless former U.S. President, whose wrath they incurred after permanently disabling the time travel device Edan had built. Working in his underground lab, Edan has now succeeded in creating a miniaturized version of the device, intended for use as a speed enhancement and fuel saving device for military aircraft. Its success would provide the U.S. with a significant strategic advantage in the air over its foes. Testing takes place at Edwards Air Force Base, supervised by Edan and Sim's long-time compatriot Dale Bowdoin, with a military drone aircraft piloted remotely by Sim. Early successes lead to further evaluation in a manned stealth fighter jet and brings with it the personal attention of the new U.S. Vice President. But then there is a potentially life-changing surprise, courtesy of one of the two Voyager spacecraft, hurtling through deep space, years out from Earth. This would seem unrelated to the work of Edan's team. But is it? The Vice President doesn't think so. In his mind, the deep space surprise is no less than a cosmic question the answer to which all of humanity has long sought. His fervor to be the one to find that answer pushes a tale of science, love, intrigue and some very human emotions, to the brink.