Unknown World (a.k.a. Night Without Stars) is a 1951 independently made, black-and-white science fiction adventure film from Lippert Pictures, produced by Irving A. Block, Jack Rabin, and Robert L. Lippert, directed by Terry O. Morse, that stars Bruce Kellogg, Marilyn Nash, Jim Bannon, and Otto Waldis.br pbr br Dr. Jeremiah Morley (Victor Kilian) is concerned about an imminent nuclear war. He organizes an expedition of scientists and has them use a large atomic-powered tank-like boring machine, the Cyclotram, capable of drilling down deep through earth and stone, to find an underground environment where humanity could escape the coming nuclear holocaust.br pbr The expedition (Jim Bannon, Marilyn Nash, Otto Waldis, Tom Handley and Dick Cogan) begins after government funding has fallen through and they are bailed out at the last minute by private funding from a newspaper heir (Bruce Kellogg), who insists on going with them as a lark. Romantic rivalry develops between Bannon and Kellogg for Nash, and two lives are lost to the perils of the dangerous expedition.br pbr In the end the scientists accomplish their goal and find an enormous underground expanse with a plentiful air supply, its own ocean, and phosphorescent light. However, all the lab rabbits brought with them give birth to dead offspring. Through autopsies, it is discovered that this underground world has somehow rendered the rabbits, and hence any other life form, sterile. Dr. Morley is deeply depressed by the news. When an underground volcano suddenly erupts, he fails to enter the safety of the Cyclotram and quickly perishes.br br Unknown World may have been loosely inspired by Jules Verne's novel Journey to the Center of the Earth (1864) and At the Earth's Core (1914) by Edgar Rice Burroughs.br pbr br Directed by Terry O. Morsebr br released 1951br br br pbr br Victor Kilian as Dr. Jeremiah Morleybr br Marilyn Nash as Joan Lindseybr br Bruce Kellogg as Wright Thompsonbr br Otto Waldis as Dr. Max A. Bauerbr br Tom Handley as Dr. James Paxtonbr br Dick Cogan as Dr.