Most people look forward to their annual vacations. Some want to relax and do nothing while others seek the thrill of diving with man-eating sharks or bungee jumping from a suspension bridge high above a rock canyon to stir up their paltry existence. In Danger Down Under, a group of ordinary people from different walks of life find themselves in an extraordinary position. After recently leaving the military, Gary and his wife, Amanda, are hoping a vacation to Australia will mend their strained marriage. A day of charter fishing ends with them stranded by a storm on a small island with six fellow vacationers, none of whom had any such activities in their getaway plans. It's the kind of thing that would make a body hire a new travel agent. While the group of castaways deal with their survival situation, Dr. Larry Williams, a scientist studying marine life off the northern coast of Australia, discovers an unusual chemical imbalance of unknown origin in many of his specimens. As he searches for the cause, local residents begin to disappear, throwing a panic into the police department and the authorities to mobilize and join in on the quest for answers. Research leads Dr. Williams to a library in Sydney that hints of a convoy from Germany sunk in 1943 by the American navy on its way to Japan with a cargo of nerve agent. He also finds corroborating evidence from the local hotel manager whose uncle served as a coast watcher and begins to expose the cover-up of a leak that is causing genetic aberrations in the water, one of which is an oversized Komodo dragon. Mysteriously the uncle is poisoned. Concern over the fate of the shipwrecked tourists grows as the police deal with missing people from the town, and Lt. Harry Morgan, commander of the search and rescue station, sends several vessels out to comb the area. Little does Dr. Williams know that there are forces at work trying to hamper his research and prevent him from learning any more than he already has. He eventually convinces his friend, Capt. Dave Weeks, an army officer stationed in Hawaii, to listen to his conscience and help him expose the cover-up. Risking his career and possible imprisonment, Captain Weeks steals secret files about the convoy and leaves for Australia to assist the scientist. As science and government head on a collision course, the creature prowling the strait in search of food terrorizes Gary and his fellow castaways. It has developed a healthy appetite for human flesh, by the way. Concerned that their safety is in jeopardy, they decide to launch Gary out in their life raft to hopefully run down a passing boat or plane only to have him pounded by a storm. He is finally picked up by one of Lieutenant Morgan's cutters but, thanks to the storm, no longer knows which direction he came from. The story comes to a head when Gary attempts to lead a rescue mission back for his wife and her fellow castaways before government agents can find them. Standing in their way is the government bureaucracy that wants to keep the secret intact and the creature that man's indifference has created. There are no boring 35mm vacation slides from this trip.