In the Highlander franchise, human beings born with the power of "the Quickening" become immortal if they suffer a premature death by unnatural means. After this First Death, they are ageless and cannot definitively die unless their head is removed or destroyed. From the time they are born, immortals and "pre-immortals" cannot biologically have children. Immortals can sense each other's presence and may take Quickening, the "essence" or power that makes them immortal, from another of their kind by beheading them. They duel each other across the centuries, a deadly "Game" with few rules. One day, the last few will fight during "the Gathering" and the survivor will win the Prize, the collected energy of all immortals who ever lived, enough power to conquer or destroy humanity. "In the end, there can be only one."