Time travel movies about sending people and things never made sense to me. To receive information from the future alone would be all you needed. Not only could you get stock prices or a lead on innovation, but you could also perhaps perform instantaneous, constant time computation of any function. And you'd have perfect foresight of anyone trying to disrupt you and take away your advantage.

But then maybe the future sends instructions for a machine that destroys you. Or it could be even simpler - it knows where to send you to die. So maybe you can't trust what it tells you at all. It has all the time to plan around your choices, and if you're still listening in any capacity it can coerce you to do its bidding.

Wild science fiction ideas searching for novelization, I suppose.