So the second story in the Night Clinic Anthology, Dopplegangers is about a scientific principle I read about in Science News.  They described taking light beams and splitting them in half.  Then whatever you do to one half happens to the other half.  That is the principle behind secure bank transfers. Well the only real way that a transporter in Star Treck can work is to change matter into energy, generally light.  This is the principle behind this short story, but as with any new scientific principle there can be and often are unintended consequences.  Read the story and see.