The Land Unknown

The title and credits are shown over a panning aerial view of the frozen landscape of Antarctica. We open with a shot of Capitol Hill in Washington, D.C. Capt. Burnham (Douglas Kennedy) is standing before a map of Antarctica. He describes it as, "Five million square miles of terra incognita." The assembled naval personnel are told their assignment is to facilitate the U.S. navy's geographical and meteorological mapping operations. They are also to explore a warm oasis surrounded by ice. Capt. Burnham greets Miss Margaret Hathaway (Shirley Patterson, credited as Shawn Smith). Maggie is a reporter with Oceanic Press. She apologizes for arriving late to the briefing. She is introduced to the other members of the expeditionary team. Commander Alan Roberts (Jock Mahoney) is a Geophysicist and the helicopter pilot is Lt. Jack Carmen (William Reynolds). She sits with the two for the final part of the briefing. [Note: the credits indicate Jock Mahoney's character is Harold or Hal, but he is addressed as Alan.] The ship departs for Antarctica. They approach the ice blocked coast of the Ross Ice Pack. The unexpected volume of ice will put the expedition two weeks behind schedule. Jack, Maggie, Steve Miller (Phil Harvey) and Alan Roberts depart from the ship in the helicopter. The weather report given to Captain Burnham indicates an approaching storm. He orders Lt. Jack Carmen to return at once. They spot the warm region of Antarctica. They get the call to return to base. Jack looks for a break in the clouds to get through the passing storm. A passing pterodactyl buzzes the helicopter and damages the collective control. They descend below sea level and the temperature rises. The temperature rapidly climbs to 91 degrees at 2500 feet below sea level. They finally break through the clouds and land in a tree lined landscape in the fog. Steve Miller is the mechanic and inspects the helicopter for damage. He discovers that the push-pull tube assembly has been damaged. Until or unless this can be fixed, they are stuck. Alan and Maggie look around while Jack and Steve make repairs on the helicopter. Alan tells Maggie to wait while he explores a little further. A strange anemone-like plant reaches out its tentacles, but Alan calls Maggie to see a bubbling mud spring before it can grab her. They walk back to the helicopter. Jack tries to call base from the radio with no luck. Steve continues repairs. Steve removes the tube assembly. He reminds the Lieutenant that it is made of a magnesium alloy. As he fears, trying to straighten it with a hammer causes it to break in half. They break out the survival gear and set up a camp nearby. The next day the party is awakened by a screeching sound. A pterodactyl flies over their camp. They find themselves in a primitive forest with prehistoric plants. Cmdr. Roberts notes, "It's my guess that this valley is still in the Mesozoic Era." Jack reaches down into a pool of water for a drink and comments, "Tastes like rotten eggs." They hear a search-aircraft above the cloud layer. Jack gets back on the radio to contact them. The signal is too weak to be heard. Jack starts and idles the helicopter engine to recharge the battery. Alan inflates a raft while Steve goes off in search of water. He finds a source and drinks. He looks up and sees a large, dead pterodactyl on the shore of a lake. He runs back to camp to report his find. He brings the rest back to see the creature. Before they get back to camp they find two giant lizards fighting. The larger one defeats the smaller one and then approaches the dead pterodactyl. The commotion attracts a T-Rex. Jack fires his service revolver at it with no effect. They get into the helicopter and fire up the engine. The T-Rex approaches. The spinning blades slice the creature enough to draw blood and the monster's ire. It backs away. As it approaches a second time a blaring horn causes it to leave the area. They exit the helicopter and decide to move the food and other supplies back to its relative safety in the cabin. When they get their supplies they discover some cans have been opened with a can opener. They realize they are not alone. Maggie wanders off to get a small monkey they found some water. As she approaches the helicopter she is startled by a large lizard. She drops the tarsier which is eaten by the anemone plant. She is then attacked and kidnapped by someone. He puts her in a raft and rows away. The three men search for her. They discover human footprints and a scrap of her clothing. Maggie's abductor takes her down river to a shelter. He carries her inside. The men take their raft down river in search of her. Maggie wakes to the sound of a fire crackling. Her abductor stands, turns around to look at her. When Maggie inquires about her colleagues and food she is told, "The whole valley is mine. Everything in it belongs to me, including you." He tells her the others are dead. But she sees the men rowing towards her in the raft. She engages her abductor, Dr. Carl Hunter (Henry Brandon) in conversation, stalling for time. He accosts her and she screams. Jack, Alan and Steve rescue Maggie. They ask Dr. Hunter how he got here. The 1945 expedition is the reply--a plane crash with four aboard. He finally remembers his name is Dr. Carl Hunter. Hunter hands Steve the broken push-pull tube. He tells them, "After we crashed, I stored some of the wreckage." He proposes a deal--the location of the wreckage for the woman. They do not accept the deal. They take Maggie and depart. Dr. Hunter goes out on his mission of destroying dinosaur eggs. He uses a conch shell to create a sound that repels dinosaurs. Alan and Maggie encounter the T-Rex again. It chases Alan as Maggie is menaced by the flesh eating plant. She is entwined in its tentacles. Hunter was there watching her. He hacked a few tentacles off then left. They calculate they have about three days left before the winter begins and the continent is frozen over from any rescue attempts. Jack and Steve leave camp to resume their search for the previous expedition wreckage. Alan and Maggie wander off also. Maggie steals off, boards their raft and rows down the river. Under the water is another larger menace. She rows back to Dr. Hunter's dwelling, but she is followed by the underwater creature--a Plesiosaurus. It approaches Maggie's raft. She has her back to the aquatic menace and can't see it, but Hunter does. He approaches in his own raft with two lit torches. He blows his conch horn to deter the Plesiosaurus and to alert Maggie. It approaches close enough to allow Hunter to jamb a lit spear into its mouth. The creature submerges to put out the fire. It approaches again and gets the second lit spear in the mouth. Hunter ties his raft to Maggie's raft. He rows the two back to his dwelling. Steve sees Hunter carry Maggie into his dwelling. He follows and enters the cave. Steve and Hunter fight. Steve gets the upper hand and tortures Hunter with fire to reveal the wreckage site. Jack and Alan arrive. Alan intercedes and stops Steve's "questioning method." Hunter gives Alan a map of the wreckage site. Maggie chooses to stay with Hunter and attend to his wounds. Using the map, Jack, Alan and Steve find the graves of the earlier party and the aircraft parts. Steve finds a part that will work. While Steve makes the repairs, Alan collects their winter clothes. Jack fires up the engine, but it sounds intermittent. Maggie hears the engine and decides to return to camp. As she nears the cave exit the Plesiosaur returns. Maggie is knocked to the cave floor below. Hunter picks her up and takes her outside. As the men make adjustments to the helicopter, the T-Rex returns to menace them again. They lift off before it gets to them. They fly a few hundred yards down towards the river. They use a winch to pull Maggie aboard from Hunter's raft. The Plesiosaur surfaces and chases Hunter in his raft. When the beast sees the flaming torches he dives under the water. It surfaces under the raft toppling Hunter into the water and extinguishing his spear. It crushes Hunter with its flipper. Before it can eat him, Alan fires a flare into its mouth. It submerges to extinguish the flame. Alan jumps from the helicopter and wraps the harness around Hunter. The two are hoisted aboard. They fly out of the valley. They contact base and fly back to the ship. Dr. Hunter regains consciousness. They spot the ship, but they are dangerously low on fuel. The helicopter crashes in the ocean just short of the deck of the ship. All five are rescued. On deck sometime later, Alan and Maggie are dried and dressed. Alan tells Maggie there will probably be another expedition next year. "Would you like to come along?" he asks. "No thanks, I've had it," is her reply. He suggests it as a honeymoon. They kiss. We close with a long shot of a group of ships on the ocean.