Desperate to win over Medusa's heart, Hercules pays a visit to a powerful witch, Circe. But events take a malevolent turn when Hercules realises he has unleashed a potent but toxic enchantment that threatens to turn his burgeoning hope into unbearable grief. With a bitter chain of events rapidly unfolding, it is up to Jason to undo history before it is too late. As he re-traces Hercules's steps into the mountains he is unaware that a deadly trap has been set for him; one with far-reaching consequences beyond the fate of just his friends.

The boys gain an unexpected addition to their workforce with the arrival of Pythagoras's feisty younger brother, Arcas. Charged with escorting a valuable cargo across the desert, the gang travels into the unknown with a ramshackle caravan of strangers.

It is not long before their journey takes a decidedly spooky turn; after spending a night in a temple dedicated to the Furies, it soon becomes clear that one amongst their number has something to hide. As danger closes in and a dark secret is exposed, our heroes are forced to confront some uncomfortable truths as they fight for their lives under the desert sun.