Kineas, the Athenian cavalry commander, has come a long way since being dismissed from the army of Alexander and vengefully exiled by his own city. Together, his mercenary force and their Scythian allies have defeated a mighty Macedonian army at the Ford of the River God, and his adopted city of Olbia is now free once more. But his destiny will not allow him to enjoy the fruits of victory for long. Far to the east, at the farthest edge of the Sea of Grass, Alexander is threatening to crush the Scythian hordes once and for all. 

An action-packed tale of betrayal and revenge set amid the war between Alexander the Great's generals and climaxing in the most spectacular battle of the ancient world. Satyrus and Melitta, twin heirs to a rich kingdom on the Black Sea, become desperate fugitives when their mother, the Scythian warrior-princess Srayanka, is cut down in a savage act of betrayal. Accompanied by their tutor, the Spartan Philokles, they must make a perilous journey west, pursued by ruthless assassins, to find sanctuary with the army of their father's closest friend, Diodorus. 

On the plains of Marathon an army of slaves gathers. Under Darius the Great, King of Kings, the mighty Persian army - swollen by 10,000 Immortal warriors - have come to subjugate the Greeks. In their path stands an army of freeborn Athenians and among them is fearsome and cunning soldier-statesman, Xanthippus. Knowing defeat means slavery lends keenness to his already sharp blade. Yet people soon forget that freedom is bought with blood.

Arimnestos of Plataea is a man who has seen and done things that most men only dream about. Sold into slavery as a boy, he fought his way to freedom - and then to everlasting fame: standing alongside the Athenians at the Battle of Marathon where the Greeks crushed the invading Persians. Sometimes, however, a man's greatest triumph is followed by his greatest sorrow. Returning to his farm, Arimnestos finds that his wife, Euphoria, has died in childbirth, and in an instant his laurels turn to dust. But the gods are not finished with Arimnestos yet.

Arimnestos of Plataea was one of the heroes of the Battle of Marathon, in which the heroic Greeks halted the invading Persians in their tracks, and fought in the equally celebrated naval battle at Salamis. But even these stunning victories only served to buy the Greeks time, as the Persians gathered a new army, returning with overwhelming force to strike the final killing blow. For the Greeks, divided and outnumbered, there was only one possible strategy: attack. And so, in the blazing summer of 479 BC, Arimnestos took up his spear one final time at the Battle of Plataea.