Time travelers

It was supposed that Liam O'Connor die in the sea in 1912 And it was supposed that Madi Carter die on a plane in 2010 And it was supposed that Sal Vikram die in a fire in 2026 However, moments before their death, a person appeared and said to each of them "Hold my hand..." But Liam, Madi, and Sal did not survive, but were recruited for the benefit of an agency unknown to anyone, for one and only purpose: to fix the damaged history. Because time travel happens, and because there are people who may return in time and change the past... Therefore, time travelers have appeared to protect us, to prevent time travel from destroying the world...