Bitter Seeds

Bitter Seeds is a 2010 alternate history novel by Ian Tregillis, the first book in the Milkweed Triptych. It depicts a World War II in which Nazi Germany fields soldiers with surgically enhanced psychic abilities while Britain counters by conscripting warlocks who make blood pacts with supernatural entities. The novel blends espionage thriller conventions with dark fantasy and alternate-history military fiction.

Bitter Seeds is followed by The Coldest War (2012) and Necessary Evil (2013), completing the Milkweed Triptych. The trilogy spans multiple decades of its alternate 20th century, with the sequels exploring the Cold War consequences of the supernatural arms race established in the first book. The series was published by Tor Books.

The novel features two opposing supernatural systems: German agents with powers such as precognition, invisibility, and fire-starting, derived from implants in their bodies; and British warlocks who summon beings from another dimension called the Eidolons by making increasingly costly blood sacrifices. The Eidolons alter probability and reality but exact a terrible price from the summoners. The escalating costs of both programs drive much of the plot.

Bitter Seeds launched Tregillis's career and is the opening volume of the Milkweed Triptych, his first published series. Tregillis later wrote the Alchemy Wars trilogy, set in an entirely different alternate-history universe involving clockwork automata. He has also written stories set in George R. R. Martin's Wild Cards shared universe, but the Milkweed Triptych stands as a self-contained completed trilogy.