“The line numbers of the poem could have been counted then, of course,” he was saying, “but how, in the late sixteenth or early seventeenth century, could they know the painting would become NG34, two hundred years on?”

Four faces stared, and a skeptical laugh escaped Alex. “You might as well add that Philip’s Spain now has a dialing code of thirty-four, when you telephone!” It was an absurd coincidence, but it was nonetheless wonderful. At some level it spun out various existentialist questions. Was life copying art to an exaggerated degree?

Lucy carried on the idea. “I love it! But add it to the previous text. ‘Where did I leave the sweet lady sleeping?’ I’ve developed real empathy for Ariadne, the sleeping lady left on Naxos by Theseus. Titian paints her watching Theseus disappear, yet also reaching for Dionysus, or Bacchus. His Ariadne doesn’t have to die, but gets a new heart from the kindest of the Three Fates—a reprieve. She’s elevated to a goddess for rescuing man from the labyrinth. That painting is one of the stars of the National Gallery too, and might solve that text, I feel.”

Alex leafed through the pile of sheets and found the right one, making a point of ticking it with his pencil, and setting it aside with those they’d discussed. “Is that five down? What about this one, concerning the River Styx? It has another reference to Venus and Adonis, but we renamed the Thames as River Styx for the night of our cruise, Lucy, and we had to pay the ferryman, and pass the grim reaper.” Alex turned to his father to explain. “For the hospitals’ Halloween night.”

“Alex,” Lucy answered him, “the ‘celestial goddess of light,’ and the man who ‘passes in reality into the Fortunate Isles of the Soul’…” They waited for her to explain her ideas, but she couldn’t express what she wanted to say. It was too strange to share. She remembered the thud of her heart when they’d seen the strange barge. She suddenly understood that was forty days and nights after her operation, and Will’s death. Like Christ in the wilderness, or Moses on Sinai, or the Egyptians’ period of purification of the mummy, it was the length of time a soul was thought to wait in limbo. Was his heart staying with her, and his soul departing for Elysium? She only said: “The whole document is our chronicle.”

And Alex’s response astonished her. He smiled softly. “Yes. It is.”