In the extraordinary Worldwar tetralogy, set against the backdrop of World War II, Harry Turtledove, whom Publishers Weekly has called the "Hugo-winning master of alternate SF," wove an explosive saga of world powers locked in conflict against an enemy from the stars.

In this extraordinary World War II alternate history, master storyteller Harry Turtledove begins with a big switch: what if Neville Chamberlain, instead of appeasing Hitler, had stood up to him in 1938? Enraged, Hitler reacts by lashing out at the West, promising his soldiers that they will reach Paris by the new year.

In the Hereditary Tyranny of Tartesh, what was once a vast sea basin is now a dried-out, unforgiving desert. When the kingdom's enemies try to shake down the Barrier Mountains and let the ocean in, Trench Park tour guide Radnal vez Krobir must stop them or be destroyed along with everything he holds dear. Down in the Bottomlands received the 1994 Hugo Award for Best Novella.

In the Hugo Award nominee Forty, Counting Down, computer genius Justin Kloster travels to the past to stop himself from making a terrible mistake. But all actions have their consequences. Then, in Twenty-One, Counting Up, Kloster's college life and romantic dreams are rudely interrupted when the 40-year-old Justin arrives from the future to save him from himself.

Following Blood and Iron and The Center Cannot Hold, The Victorious Opposition triumphantly concludes Harry Turtledove's American Empire trilogy - a masterful saga of alternate history. War is brewing yet again as the U.S.A. struggles to occupy Canada, and the C.S.A. begins forcing blacks into concentration camps.

In 1914, they called it The Great War, and few could imagine anything worse. For nearly three decades, a peace forged in blood and fatigue has held sway in North America. Now, Japan dominates the Pacific, the Russian Tsar rules Alaska, and England, under Winston Churchill, chafes for a return to its former glory. But behind the façade of world order, America is a bomb waiting to go off. Jake Featherston, the megalomaniacal leader of the Confederate States of America, is just the man to light the fuse.

On December 7, 1941, the Japanese launched an attack against U.S. naval forces stationed in Pearl Harbor, Hawaii. But what if the Japanese followed up their air assault with an invasion and occupation of Hawaii? This is the question explored by Harry Turtledove in Days of Infamy, with frightening implications.

In the real world, Reinhard Heydrich, the number-two man in the SS and an architect of the Holocaust, was assassinated in Czechoslovakia in May 1942. In The Man with the Iron Heart, Heydrich survives that fated assassination attempt, only to hatch an insurgency as insidious as anything conceived by Osama bin Laden.

In the 21st century, Germany's Third Reich continues to thrive after its victory in World War II - keeping most of Europe and North America under its heel. But within the heart of the Nazi regime, a secret lives. Under a perfect Aryan facade, Jews survive - living their lives, raising their families, and fearing discovery.... 

WWII sniper Caje Cole embarks on a rescue mission behind the new Iron Curtain for American POWs held as political pawns by Russian forces. To free them, he will have to defeat his deadliest adversary yet, the Red Sniper. The brutal Russian believes that he can outgun anyone, but he hasn't met the likes of this backwoods hunter and marksman. 

Ufthak Blackhawk and the green tide descend upon Hephaesto - an Adeptus Mechanicus forge world bristling with loot - only to find it already under siege by the notorious Freebooter Kaptin Badrukk. When his warboss, Da Biggest Big Mek, orders temporary co-operation, Ufthak seeks to make a name for himself by crushing some of the Imperium’s most advanced defenders and claiming the greatest prize. 

Humanity has colonized the planets - interstellar travel is still beyond our reach, but the solar system has become a dense network of colonies. But there are tensions - the mineral-rich outer planets resent their dependence on Earth and Mars and the political and military clout they wield over the Belt and beyond. Now, when Captain Jim Holden's ice miner stumbles across a derelict, abandoned ship, he uncovers a secret that threatens to throw the entire system into war.

World War Three wiped out the humankind. The planet is empty now. Huge cities became dust and ashes. Railroads are being eaten by rust. Abandoned satellites hang lonely in their orbits. Radio is mute on all frequencies. The only survivors of the last war were those who made it into the gates of the Metro, the subway system of Moscow city. It's there, hundreds of feet below the ground, in the vaults of what was constructed as the world's largest air-raid shelter, where now people try to outlive the end of days.

We were fighting on the wrong side of a war we couldn't win. And that was the good news. The Ruhar hit us on Columbus Day. There we were, innocently drifting along the cosmos on our little blue marble, like the native Americans in 1492. Over the horizon come ships of a technologically advanced, aggressive culture, and BAM! There go the good old days, when humans only got killed by each other. So, Columbus Day. It fits. When the morning sky twinkled again, this time with Kristang starships jumping in to hammer the Ruhar, we thought we were saved.

On an Imperial outpost world on the fringes of tau space, the renowned Commissar Ciaphas Cain and his fractious regiment of Valhallan Guard, newly created from the remnants of two devastated units, find themselves in the middle of a war. As the Astra Militarum struggle to contain worldwide civil insurrection, can the wily Commissar Cain identify the real villain before the planet is lost to the Imperium forever?