The United States of Europe, the new nation formed by an alliance between the Swedish king Gustavus Adolphus and the West Virginians hurled back in time by a cosmic accident--the Ring of Fire--is beset by enemies on all sides. The U.S.E. needs a reliable source of opiates for those wounded in action, as well as other goods not available in Europe. The Prime Minister of the U.S.E., Mike Stearns, sends a mission to the Mughal Empire of India with the aim of securing a trade deal with the Mughal emperor, Shah Jahan.

The mission consists of a mixed group of up-timers and down-timers, including paramedics, a squad of soldiers with railroad-building experience, a spy and a pair of swindlers. On reaching India the mission finds a grieving emperor obsessed with building the Taj Mahal, harem-bound princesses, warrior princes, and an Afghan adventurer embroiled in the many plots of the Mughal court.

The emperor's sons are plotting against each other and war is brewing with the newly risen Sikh faith. But in the midst of these intrigues, the U.S.E. mission finds a ally: the brilliant and beautiful Jahanara Begum, the eldest daughter of Shah Jahan. She is the mistress of her father's harem and a power in her own right, who wishes to learn more of these women who are free in a way she can scarcely comprehend.

When the Emperor learns of what befalls his empire and children in the time that was, he makes every effort to change their fate. But emperors, princesses, and princes are no more immune to the inexorable waves of change created by the Ring of Fire than are the Americans themselves.

About Eric Flint's groundbreaking Ring of Fire series:
"This alternate history series is . . . a landmark..."--Booklist

About Eric Flint's best-selling Jao Empire series coauthored with K.D. Wentworth and David Carrico:
"The action is fast and furious . . . a trimphant story . . . "--The Midwest Book Review

"Building to an exhilarating conclusion, this book cries out for a sequel."--Publishers Weekly

About Eric Flint's Boundary series, coauthored with Ryk E. Spoor:
". . . fast-paced sci-fi espionage thriller . . . light in tone and hard on science . . ." --Publishers Weekly on Boundary

"The whole crew from Flint and Spoor's Boundary are back . . . Tensions run high throughout the Ceres mission . . . a fine choice for any collection." --Publishers Weekly on Threshold

"[P]aleontology, engineering, and space flight, puzzles in linguistics, biology, physics, and evolution further the story, as well as wacky humor, academic rivalries, and even some sweet romances." --School Library Journal on Boundary