The Last Man On Earth Season Finale: 10 Big Questions That Need Answering

When Todd first arrived at Tucson he interrupted the final moments before Phil got down with Melissa. That lead to much jealousy from Phil, to the point that he decided to drive Todd out in the desert and abandon him there.

Phil ultimately could not go through with the attempted murder plot and played it off like he was kidding. That's the story that Todd believed until he felt a case of jealousy of his own against new Phil.

Todd would vent his frustration with the equally upset Tandy (old Phil). Tandy would talk about murdering Phil and Todd seemed to be on board. When he asked Tandy how they would go through with it, Tandy explained that the two would simply drive new Phil out into the desert and drop him off. He would be without sustenance in the dry and hot terrain, left to die.

Todd realized that Tandy had pulled the same stunt on him and became enraged. He told the rest of the community about Phil's plan, turning everyone against him. 

With the exception of new Phil, everyone seemed willing to accept Tandy back into the fold after a few days. Despite Todd's involvement in the group there would still need to be at least a good talk between him and the man who almost killed him.