Tir Nan Og - the Land of the Young, deep in Celtic myth and legend. Barbarian warrior Slaine and his dwarf companion Ukko have joined forces with trainee priestess Nest and are travelling by dragon to the fortress of the Ever-Living Ones, under attack from dark gods, the Cythrons. The arch-druids within the eternal fortress have plans to send Slaine through time to save the human race. He is to be their Time Killer!