"A simulation," she said. "Meaning what?"

"We can make waves up to one meter high in this tank," Marshall said. "But the real tsunamis are four, eight, ten meters high. Occasionally even more."

"A wave in the ocean that is ten meters?" Her eyes widened. "Really?" She was looking toward the ceiling, trying to imagine it.

Marshall nodded. That would be over thirty feet high, the height of a three-story building. And it would be moving at eight hundred kilometers an hour, roaring up to the shore.

"And when it comes to the shore?" she said. "Is that the slope at this end? It looks like a pebble texture on it. Is that the shore?"

"That's right," Marshall said. "How high the wave goes up the shore is a function of the angle of the slope. We can adjust the slope to any angle."

The boyfriend came forward, moving closer to the tank, but still he hung back. He never said a word.

Marisa was excited. "You can adjust it? How?"

"It is motorized."

"To any angle?" She giggled. "Show me vingt-sept degrees. Twenty-seven."

"Coming up." Marshall typed at the keyboard. With a slight grinding sound, the slope of the shore angled higher.

The American boyfriend went closer to the tank to look, drawn by the activity. It was fascinating, Marshall thought. Anybody would be interested. But the guy never spoke. He just stood and watched the pebbled surface tilt. Soon it stopped.

"So that is the slope?" she said.

"Yes," Marshall said. "Although in point of fact, twenty-seven degrees is fairly steep, more than the average shoreline in the real world. Maybe I should set it to"

Her dark hand closed over his. "No, no," she said. Her skin was soft. "Leave it. Show me a wave. I want to see a wave."

Small waves were being generated every thirty seconds. They rippled along the length of the tank, with a slight whoosh. "Well, I first have to know the shape of the shoreline. Right now, it's flat beach, but if it was an inlet of some kind amp;"