“A snake?” Cassandra shone the light on the burlap and saw slow movement inside. “There’s been a snake in here the whole time?”

“Mm-hmm. The cold keeps her still.”

“So.” Cassandra turned the bag. “If you’re not sure your blood will work, why don’t we just start with the snake?”

Athena snatched the bag back. “I like this snake.”

Once the snake was safely in the belly of the boat, Athena put the knife to the palm of her hand and nudged one of the oars toward Cassandra. Cassandra grabbed it as the blade dug deep into the meat of Athena’s palm. The blood pooled for a few seconds, and then she tipped it over the side in a steady stream as if from a chalice. Her lips moved in a soundless prayer or incantation, and she plunged her hand into the water.

“Push us out, Captain.”

*   *   *

They moved off into the dark, slowly at first, and then faster. The water against Athena’s wrist stung like blades of ice. She fought the urge to pull her hand out, had to force herself to leave it below the surface, trailing like chum to the sharks, to every monster and beast that lurked in the water below the paper-thin belly of the boat. Some hideous child of Keto might twist out of the depths and tear her hand off with rows of triangular teeth. Or worse, they could drag her down to be crushed in the dark between scaly coils.

But no matter how her teeth threatened to chatter, she kept her voice calm. Cassandra was still afraid.

“That’s good,” Athena said. “Good. Don’t worry about direction. I can feel the current now. It’s taking us.”

Cassandra nodded, and Athena realized she could see her outside of the flashlight beam. The dark wasn’t so complete. The current grew stronger against her fingers, and she detected a hint of warmth, separate from the steady stream of blood pulsing from her palm.

“Athena? I think it’s working.”

Light came up slowly, light the likes of which only existed in one place. Orange and rosy red at once, it cast no shadows. The light of the underworld. Athena pulled her hand out of the water: a sad, pale, empty thing that throbbed and ached. She wiped it on her jeans and balled it into a fist.

“Here.” Cassandra nudged her and handed her a long white sock. “For your hand. And it’s not off my foot; it’s out of my bag.”

“Thanks.” Athena tied it around her palm. “We’re almost there.” Banks of black rocks and sand appeared on both sides of the broad waterway. She almost told Cassandra not to look up. The expanse over their heads would make her dizzy to the point of vomiting. But it was better not to. If she told Cassandra not to do it, she’d do it for sure.

“What river are we on?” Cassandra asked. “Acheron, or Styx?”

Acheron or Styx. The river of pain or the river of hate. Not much to choose from, but no rivers of dancing ponies led into the underworld. Athena leaned over the side and scooped up water. She pushed it into her mouth, swished it around, and spat.

“Styx.” She spat again.

“How do you know?”

“Don’t you know what hate tastes like?” She glanced back. Cassandra’s face darkened. Silly question. She knew better than most people. “I’m sorry,” Athena said. “It’s making my voice harsh.” She spat more. “Don’t drink it. Don’t even smell it.”

Below them and on all sides, the Styx glittered like a malevolent jewel. Achilles’ mother had dipped him in up to his heel to make him a killer of men, to make him invincible. The lengths of a mother’s love. Athena supposed it had worked. But it was difficult to imagine dunking an infant into so much hateful water.

Behind her, Cassandra looked from shore to shore with fearful fascination.

“Where do we go? It all looks the same. Which side is the one we want?”

“Probably best to ask the dog,” Athena said.

Cassandra frowned. “Cerberus?”

“Ding, ding, ding! Ten points for the princess of Troy.”

“Is this the river of hate, or the river of smartass?”

“Sorry,” said Athena. “Let’s just hope Hades’ three-headed Fido is still alive and kicking.”

Athena put her fingers to her lips and whistled. After a few seconds of tense silence, Cerberus howled back. Twice.

Twice?

They waited, but no third howl followed. Then the river turned and they saw why, as he bounded down the bank.

Two of his heads were alive and well. The third was not. It dangled from his black shoulder, a grotesque marionette of bloodstained bone and sinew that rattled as he pawed the sand.