Here’s how it happens:
I invent the first time machine. Or, Future Thom invents the first machine, then travels back in time, and gives Present Thom the schematics, so that I — that is to say, Present Me — can in turn invent the first time machine for Future Thom to deliver back to me.
Once I — that is to say, Future Thom — has completed this first leg of the journey, he/I will then go back further in time to August 1, 2002, in the city of Los Angeles, whereupon I — that is to say, Future Thom — will track down one M. Night Shyamalan, on the eve of the theatrical release of his film Signs, and I — that is to say, Future Thom — will explain this to him (that is to say, Past M. Night Shyamalan):
“I am going to kill you,” Future Thom will say, as he pulls a six-shooter from a holster hanging from his hip white Urban Outfitters belt. “I have come from the future to save you, and I will do whatever I can to save you, so I will kill you.”
Past M. Night Shyamalan will put his hands up over his head and try to defuse the situation. He’ll ask Future Thom why, what are you doing, are you mad, this can’t be happening. But it will be happening. And Future Thom will explain.
“After Signs, your career pretty much becomes a big joke of pretentious self-importance and cheesy ‘twists’ in lieu of any actual plot or purpose. Even Signs was only mediocre — honestly, you should never have shown the aliens at all, it would made the whole thing a lot better.”
“But they looked so cool…!” he’ll protest. He’ll be wrong, and he’ll know it.
Future Thom will pull back the hammer on the six-shooter and raise it to his chest. “If I kill you now, you’ll be forever remembered as a visionary young filmmaker, stolen away from the world before his time in some mysterious, unsolved murder. Your name, your legacy will never be sullied by such crap as Lady in the Water or The Happening. You will become the legend you have always aspired to be, and you will have me to thank for this.”
“Okay,” he will say with forced bravado. “Do it.” He won’t actually believe me, but when a mad man claiming to be from the future holds a gun to your chest, sometimes it’s best to just accept it.
“It’s for your own good,” Future Thom will say. “Killing Baby Hitler raises too many questions. But killing you will save us all.”
Future Thom will pull the trigger. You will never read this story, because I will never have invented a time machine to go back in time to kill M. Night Shyamalan, because M. Night Shyamalan was mysteriously killed the night before the theatrical release of Signs, and the inexplicable and perplexing story of his death will be remembered for generations to come.