Ariadne – now queen and in an epic war against Pasiphae's army – turns to Jason, Hercules, and Pythagoras for help. The time has come for Jason to fulfill his destiny. The battle for Atlantis has begun.

Atlantis is set to fall as Pasiphae continues her siege on the city. The last hope rests with Jason, Hercules, and Pythagoras. Hercules makes a discovery that throws into doubt everything he once knew to be true.

Ariadne is formally crowned queen of a still-vulnerable Atlantis. An enigmatic stranger arrives offering salvation. As Jason fights for glory on the tournament ground, Ariadne embarks on her own private battle.

As plans progress for the royal wedding, Ariadne must undertake a journey to Telemon’s homeland of Aegina. With the kingdom still beset by Colcheans, Jason is not the only one who fears for the Queen’s safety.

The gang find themselves dispersed around the ancient necropolis and they soon realize they are not alone...the space is crawling with a magical army of the undead. The race is on to find Jason before he falls prey to the flesh eating monsters.

As Ariadne lies on her deathbed, Jason embarks on a dangerous quest into the unknown. After a daring encounter with the ancient Grey Sisters, Jason's mission brings him face to face with Medea and Pasiphae once more.

When news reaches Pasiphae of Ariadne and Jason's impending marriage, she is terrified that Atlantis will be lost to her forever and resolves to do all she can to stop the union, no matter the cost.

Pasiphae realises she will never be true ruler while ever she and Ariadne both have a claim to the throne, so she offers the queen her freedom – if she will renounce the crown. As wanted men, Jason and Hercules have been forced to seek refuge in the mountains, where Medusa and Pythagoras come up with their own plot, which will take a sacrifice of unimaginable proportions.

Jason's discovery has blackened his heart, leaving him a shadow of the man he used to be. Reckless and foolhardy, he no longer seems to care about anything or anyone - even Ariadne. Pythagoras is desperate to save his friend, so he sets out in search of help, but soon discovers not everyone is as keen to protect Jason as he is.

The battle between Aeson and Pasiphae for Jason's soul reaches a devastating climax as the warrior is caught by the ruthless queen's soldiers. Jason's friends know they must do all they can to save him before he is lost for ever, and Aeson undertakes a brave and deadly mission into Atlantis to rescue his son. However, he is just one man, and with traitors on all sides plotting to stop him, his chances of success seem slim.

Jason is determined to rescue his fellow prisoners from the amphitheatre, and makes a daring return to Atlantis, which is becoming an ever more dangerous realm under Pasiphae's villainous rule. The hero and his friends face treachery at every turn, and come to realise that the only hope for the future is to kill the queen.