Time machines create questions. What happens when events from the future change the past?
Do world events unfold as a future newspaper predicts? What happens to a wine glass from the future, if its present counterpart is shattered? Would identical seeds from the future and past grow into identical plants? What happens to love if your past is altered before the attraction began? How do the paradoxes resolve?
The ultimate paradox is an infant sent back through time. His arrival in that past alters history so that he is never conceived. He should not exist, and the impossibility of his life grants him the special ability to see changes to timelines. When he discovers the reason for his gift, it sets in motion a struggle of hard choices and time manipulation.