Laura takes Mattie to tell her the truth about her past and shocks her by telling her that she accidentally killed her brother when she was watching him for her parents when he ran out the house and got knocked down and her parents have hated her ever since. Mattie is excited she has grandparents, but also shocked at they way they have treated her.
Mattie runs to Leo when Mia shows back up and realizes how they might be able to save her. Together, they unite in order to save her. Once they do, Joe pops back up and calls the police on Leo and it leads to Max having to sacrifice himself in order to save Leo. He jumps into the river -- a certain death.
Kate comes clean to Pete, who runs away from her because his ex is sleeping with her synth.
Niska hangs out at George's house and they chat about all things synth, until Pete shows up and gets ready to arrest George if he's been hiding Odi from him.
Edwin makes some progress in his quest to find all of the super synths.