Beyond the Mist (Lake Lanier Mysteries, #2) by Casi McLean

Great second story to this series. Going back to 2001 is always a tough read, but to be able to go back and try to help. But does helping the past change the future? Nick didn't care he wanted to go back and make a difference, and Piper wanted to go back and save Nick. Now they both have to work to get back to where they belong.
This is a great story about time travel, trying to help others, and not giving up on true love.