Alternate by Ernie Luis

Synopsis:

In 2020, Greyson Tolbert’s daughter died at eight years old. In 2030, he became the most lethal assassin for the Watchtower, a secret organization that uses time travel as a means to bend reality in their favor. If he works for them long enough, he’ll get to go back and save his daughter. Or so they say… 

Now, after a fellow assassin goes rogue, Greyson learns the truth behind the Watchtower, all its dirty secrets, and all the promises they’ve failed to keep. With the timelines hanging in the balance, Greyson must choose between saving the past, or saving the future.