Wordless, we moved on, bearing the great skin carefully between us. Cathal, I thought, you will have an amazing tale to tell your baby son or daughter one day. Unbidden, a vision came to me. It was the same little house I had seen once before, the same window opening onto trees, the same mellow lamplight over the peaceful interior. I was there, before the hearth. Felix was seated opposite me, restored to perfect health, his color high, his glossy hair tamed by a ribbon at the nape. The child on his knee was older than she had been last time; instead of an infant’s smock she wore a little gown embroidered with owls. Her big eyes were fixed on her father in fascination as he told her a story. And then your mother walked up to the serpent, right up to it, and it lifted her in its hand. Our daughter protested, But Papa, serpents don’t have hands. They are the same as snakes only bigger. Aren’t they? He smiled. This one had hands. Hands with long sharp claws. Perhaps it was not so much a serpent as a sea dragon. Your mama is the bravest woman in all Erin. Our daughter turned her beautiful eyes on me for a moment and said, I know that, Papa. Tell me what happened next.

The vision began to fade. I stumbled, desperate to keep it, desperate to say, I love you, I wish with all my heart that you were real, don’t go! Foolish Sibeal.

“Wait.” Cathal stopped to adjust his grip. “Are you all right?”

“Fine,” I said grimly. “Prey to unhelpful thoughts, that’s all.”

“I know how that feels.”

We reached the water sooner than I expected. Or maybe the water came higher up the tunnel now. We splashed in, our awkward bundle between us. Here, there were fewer of the little lights. My facility for natural magic was limited; beside Ciarán’s it was nothing.

“I told myself I wouldn’t think about Clodagh.” My companion’s voice came to me softly through the half-dark. “But I’ve thought of nothing else, all the way.”

“Hope,” I said. “Leading you forward. The knowledge that home is waiting for you when the mission is over.” Even as I spoke, it came to me that my idea of what home meant had changed entirely over this summer. What was waiting for me?

Silence for a while, as we moved on through the water. Now it was almost up to my knees. “I don’t suppose it matters,” I said, “if we get the skin wet.” I imagined the sea creature leaping and diving in the bay, at one with the waves.

“I suppose not.”