Mnemosyne.
The titaness had been spared after the Titanomachy—the war in which Hades and his brothers, Zeus and Poseidon, had risen up against their father and the other titans to tear them down and take their place as rulers of this world. Hades had given her a new life and a new purpose in his realm while her male counterparts rotted in Tartarus, and she had repaid that kindness by turning on him. He should have locked all the titans away—both male and female—rather than being merciful to some.
Being weak.
Mnemosyne had exploited that weakness, using her freedom to plot, plan, and gather herself an army, turning his own people against him and poisoning them with promises of realms to rule if they succeeded in tearing Hades down.
She had even managed to evade suspicion by being incarcerated in Tartarus for a minor crime at the time Calistos and Calindria had been captured. When her term had ended a century or so later, he had turned her out into his realm and allowed her to go on her way.
Anger blasted through him, heating his blood, but his mask of ice remained, hiding the sudden surge of emotion from Eris and Thanatos.
He would find the titaness, and when he did, she would pay.
In the wake of anger came the familiar restlessness, impatience that had been slowly gnawing at his sanity for months now, since the demigoddess had revealed Mnemosyne’s role in the uprising and he had begun to scour the Underworld for her. She had gone to ground and she had covered her tracks well. His legions were searching every corner of his realm for her, and his sons were doing the same in the mortal world. Even Enyo, his eldest son’s beloved, was seeking Mnemosyne, checking every corner of Olympus for the traitor.
Eventually, Hades would find her.
But it weighed on him.
Every second she remained beyond his grasp was a second she could launch an attack, a moment in which she might succeed in her plan.
And the longer she evaded him, the stronger she would become.
He had no doubt in his mind that the titaness was raising a new army for herself, replacing the soldiers she had lost as she formulated a new plan.
Hades narrowed his eyes on Eris as she realised she would receive no help from her brother and her bleak amber gaze drifted back to him.
As he stared into her eyes, the weight on his shoulders became crushing. It squeezed the air from his lungs and tightened his chest, until he was close to gasping for air as she had been. He needed to end this. Now. Before it was too late.
Before something terrible happened.
He was god-king of the Underworld, responsible for his realm and all in it, and the crown he wore had always felt heavy, but never as heavy as it did now.
So many of his sons had fallen in love with mortals or Carriers—humans with blood of his realm in their lineage—and he felt responsible for the fate of that world too now. If he couldn’t stop Mnemosyne, all would be lost.
And his family would face a terrible fate.
He couldn’t stop his gaze from shifting to his left, to Thanatos. If the titaness won, even the god of death wouldn’t be spared to carry out his duty of severing the threads of life from Hades and his family now that the male was wed to Hades’s daughter, Calindria.
For the first time since the grim male had stepped foot into the room, a flicker of emotion coloured his irises, lighting them with ethereal blue. Thanatos knew his thoughts. Knew the darkness that tormented him. He could see it in that blue shimmer. Thanatos knew it because it tormented him too.
Probably stole sleep from him as it did Hades.
Did Thanatos lay awake to watch over his beloved, fearing this glimpse of her might be his last and too afraid to tear his gaze away?
Hades did.
The thought of losing Persephone tore at his soul, bathing it in darkness, and he curled his fingers into fists at his sides. He stared at Eris, seeing Mnemosyne in her place as she choked and began clawing at her throat again, her eyes wild as they sought her brother, seeking help where she would find none.
Mnemosyne would know the full extent of his wrath when he got his hands on her.
For every betrayal she had wrought, she would receive a million lashes from his shadows. For every member of his family, she would receive a million more. He would whip her until she had no more blood to give. Until she teetered on the brink of death. And once she was there, desperate and pleading with him in the way Eris beseeched her brother, he would let her heal and do it all over again. And again. Until he ripped the last shreds of her sanity from her.
And then he would discard her in the deepest pit in Tartarus and let her rot.
Her new home would be a cell that Cassandra, his son Daimon’s wife, was helping him construct. One that would be strong enough to contain the titaness thanks to a combination of Cassandra’s magic and his wards.
Hades wanted to kill her for what she had done, but again, he was no fool. Killing a titan was nigh on impossible. It was the reason Tartarus was home to so many of her breed. After the Titanomachy, they had tried to kill the titans, but found they didn’t possess the power to do it.