I Spoke to the Past and Changed the Whole World

When Yang Tian woke up, he found a calling app on his phone that he couldn't uninstall.

For just one cent, he could call people in the past.

So...

Yang Tian called himself from yesterday: “Go buy a lottery ticket. The numbers are...”

Yang Tian called his parents from ten years ago: “Mom, Dad, go buy a house in...”

Yang Tian called the police station from twenty years ago: “Hello, get to Times Square. Someone is trafficking people.”

Yang Tian called someone from a hundred years ago...

One day, Yang Tian received a mysterious call: “I'm you, a thousand years in the future...”