21 GRAMS: Boston medic Dr. Duncan Macdougall sets out to scientifically prove the existence of the human soul, by weighing a man at the moment of death. If the patient loses weight, Macdougall believes he will have recorded the departure of the man's soul, and science will have shown religion to be right. But finding subjects willing to die on cue is not an easy task. His experiment, and results, remain controversial to this day. Is 21 gram the weight of a human soul? MISSING COSMONAUTS: The dawn of the space age. Two amateur radio hams are listening in, recording broadcasts from early Russian launches into space. One day, they hear a heart-stopping sound. Someone tapping out a distress signal from space. Was cosmonaut Yuri Gagarin really the first man in orbit, or did the Soviets send others up before him? Were they erased from history because they never came back? SOUND OF DEATH: There is a weapon you have probably never heard of. Some say it has never been used in anger. And yet several governments have called for it to be banned. When French scientist Vladimir Gavreau finds his laboratory flooded with a mysterious energy that has debilitating effects on the human body, his research is taken in a menacing new direction. Did he invent a new type of weapon of mass destruction? His work, and its military uses, remain shrouded in mystery to this day.