Alastair had a rock on his desk. It had been there the whole time Willem had known him. Had it been quite a bit smaller, it might have been mistaken for a paperweight. It was an irregular oblong, smoothed by wave action, and totally unexceptional. Willem had asked him about it once and Alastair had explained that it had been retrieved from a lighthouse off the Oregon coast. The lighthouse keeper had heard a loud noise in the middle of the night and climbed the stairs to investigate. Halfway up was a window that had been smashed out by this rock. The window was a hundred feet above sea level. The only way the rock could have ended up there was by being entrained in a huge wave that had broken against the cliff on which the lighthouse stood. Alastair had somehow acquired the rock and kept it "as a memento mori" to focus the minds of shipping company executives who wanted to know (a) why insurance was so expensive and (b) why enormous ships sometimes ceased to exist without warning or explanation.