Tom Barren is a screw-up. He knows this because he's lived two difference lives in 2016 and he's incompetent in both. In fact, if he hadn't tolen his father's time machine and traveled back to 1965, we would all be driving hover cars and wearing biodegradable clothing. Instead, he corrupted the timeline, killed billion of people and caused the utopian version of 2016 to never exist.
He did, however, create a new loving family for himself and discover his soulmate. Now the Tom's of ever possible today must decide which yesterday to save and which tomorrow they'll create.