On an otherwise cloudy afternoon the sun suddenly breaks through, casting rays down onto the Andaman Sea and its Karst sentinels. “The Jesus Effect,” I say, loudly enough so Katrin can hear me over the engine’s roar and the ocean sloshing against the Thai longtail’s hull.

“What?”

“The Jesus Effect,” I say more loudly. “When the sun comes through the clouds in shimmering rays like that.”