“As the years passed, however, nothing happened. No one came, no one tried to break into the old castle. The club’s leadership decided then to simply let the secret wither and die, and the club with it. Each new generation of members would be told only part of the story and instructed to tell the next generation even less. In the meantime, the dwindling club would keep silent watch over the ruins and the paintings, just in case the rumor about an outsider knowing the secret was true. But, by now, of course, any such outsider would be long dead.”

As Kingdom said this, Alex and his grandfather shifted uncomfortably in their seats.

“It was decreed that if we kept ourselves hidden, if we let the story fade, and if nothing happened for a hundred years,” Kingdom continued, “then we could safely assume all was well, and simply disappear. Let the club die out. And so, Philippe and I are the very last members. Until recently, there were three of us left. Our comrade Ralf was from the family assigned to watch over the Rubens, The Great Last Judgment—the largest of the paintings. Ralf was president before me. He actually worked as a guard at the Alte Pinakothek museum in Munich. He was killed there the night it was taken, attempting to stop the theft.”

She paused before going on. “So. While we have sworn our lives to our cause, we only have fragments of the story left: First, that something once happened at the castle in the Black Forest, which must never happen again; second, that to prevent it happening, the paintings must never be brought together—and now, when we have no strength or influence left, it seems that they are being. This group you mentioned have already taken nine. And now they are coming for this one. We drove them off last night, but I have no doubt they will return.”

They all followed her gaze to the picture on the wall.

“Where’s the eleventh?” Alex asked. “The last painting?”

Metz started to reply, but Kingdom cut him off.

“No.” She shook her head. “The eleventh painting is our last secret. Trust can only stretch so far. To earn more, you have to give us something in return.”

“Why don’t you just take this painting and hide it?” Alex said. “Or destroy it. That’ll put an end to it, won’t it?”

“Perhaps,” Kingdom replied. “Perhaps not. There are two problems there. For one, as the last of the club, Philippe and I are sworn to stopping anyone who tries to gather the paintings together—not to run from them, not to hide from them, but to stop them. Stop the secret from being known. And so here we are, waiting for them to come.” She nodded sadly at the shotgun leaning against the table. “Who are they? Who’s doing this?”