In the first episode, host Carl Safina travels to Glover's Reef Marine Reserve, a coral atoll in the central American country of Belize. Accompanied by a team of U.S. researchers, who've been studying the reserve for eight years, Carl catches, tags and releases a wide variety of sharks. He scuba dives to check out the shark-counting instruments that the researchers have placed around the atoll, and he also visits the shark fin trader in Belize City's fish market. The fin trade now threatens sharks worldwide, but the sharks in Glover's Reef Reserve are safe and thriving.