“They took everything to these rocks,” Harry said slowly, going step by step. “I ’eard them talking, just snatches. Von Sudenfeld told them about the château and ’ow the people ’ad chased them off. Zia said something about leaving it till they were ready to go together, somethin’ like that. And then they were doin’ something. Moving among the rocks, chanting, you know, the usual malarkey. Yeah, that’s right: that’s when I grabbed the painting, they were too busy to see me, and it was just lyin’ there. But then there was a glow . . . something glowing . . . and then . . . I was running through the trees . . . and that’s all I can remember.” He shrugged apologetically.

“But the Shadow Gate, Harry,” Alex said. “You said they were talking about the Shadow Gate.”

“Yeah . . .” Harry turned to Alex’s grandfather. “That was as much as I ’eard though, just those words.”

“That’s it?” Alex said. “This is hopeless.”

“It’s not,” Alex’s grandfather said.

“It is,” Alex said. “Completely hopeless.”

“No, no. I mean, ‘It’s not.’ Remember, Harry?”

“Eh?”

“The message you left on my answer machine. You were trying to tell me something. You said, ‘Two things: it’s not . . .’ Ring any bells?”

“It’s not,” Harry repeated. He shook his head. “Sorry.” He tapped at his skull. “But there’s more . . . lurking; it’ll come back.”

“Not to worry,” Alex’s grandfather said, weary but determined. “You’ve shown us our next move. We need to get to this château for the last painting, and hope they haven’t already beaten us to it. Think you could find it again, Harry?”

“Ah.” Harry raised his eyebrows. “Got that. Memorized the address. Château de Saint-Clement, in Marsilly. Moselle, near the French-German border.”

The hotel’s owner came with news that their car would be arriving within twenty minutes.

“Just time for coffee and cake.” Alex’s grandfather beamed, grabbing for the menu again.

As dessert arrived, the old man rubbed his hands eagerly. “There are a million good reasons to visit this part of the world. But the schwarzwälder kirschtorte ranks among the greatest.” He took an ambitious mouthful, then waved his spoon in bliss. “I don’t care if it’s touristy: you won’t find finer Black Forest gateau anywhere other than in the Black Forest. Stands to reason. It’s a pudding that seems to have fallen out of fashion in Britain these days, Alex, but who knows what anyone is thinking anymore.”

“These cherries are top-notch,” Harry mumbled.