Headstrong and bullheaded Liz is pretty sure that Max killed her sister Rosa. But she was able to come to the conclusion that it was actually Isobel who did it and Max covered it up. So, now Liz has another reason to hate Max. As we are reeling from this new information, Isobel killed Rosa, we flashback into the trio’s past. And that killing someone was something that they are guilty of, maybe. Liz doesn’t care about anyone or their feelings. She just wants to know what happened to her sister. So we take a trip into the past to find out what really happened to Rosa as Max begins to tell the story of what really happened to Rosa.

It starts with them in the desert after they killed the homeless man. Isabel changed and not for the better. She would have episodes and blackouts and her personality was very different. Turns out that Rosa and Isabel had a secret friendship. Isabel is the person that Rosa was secretly hanging out with Isabel. We also stumble onto other secret friendships/relationships. Alex and Michael bonded when they were in high school and became good friends. Ales helped him out. But there are some discrepancies in those relationships. Isabel is acting funny towards Rosa and even Max is becoming suspicious of her too. But it doesn’t seem that abnormal to people I guess. Rosa is most notably affected by her change in moods. And we can actually see her shift in moods when Michael mentions that high school is almost over and their lives are changing. Isabel leaves the prom in search of Rosa and finds out that she is planning to run away and the panic in her eyes is evident.

All of the kids past’s are intertwined with all of them interacting at some point. It seems that they are more connected than they remember or are even aware of. But the dynamics of their relationships have been altered by the three aliens. Michael notices that Isabel disappeared at prom and they find her the next morning and find her asleep at Michael’s place. They get into a big fight and she tells them she feels like Max and Michael are abandoning her. So they attribute her weird behavior to this. But it is very clear that she is strange. Especially in how she seems to be obsessed with Rosa. It is evident that this persona has romantic feelings for Rosa. And she is finding that to be a little strange and offputting.

One thing that happens is that Liz and Max get to spend some alone time together because their car was vandalized by Rosa’s ex-drug customers. Isobel also sees this and she doesn’t like it because she thinks this is why Rosa is leaving. So because of that, it gives Max a chance with Liz. Or so he thinks. She shuts it down before they can get started because she has all these great plans. But after some thought, Max decides that he can’t let her go and he wants to go with her. And Liz happily agrees. But Rosa catches Max putting a note on their car and flips out on him. And Max just walks away.

Michael and Alex are caught and it doesn’t end well. As they are both leaving they boys get a high pitch keening sound in their heads and a vision with a location and what looks to be Isabel lying unconscious on the ground. But when they get there, it isn’t Isabel who is hurt. It is Rosa and the girls she used to sell drugs too. When they find Isabel she has her hand over Rosa’s mouth and she is dead. They tried to save them but in the end they had to cover it up. They made it look like an accident and fled the scene.

Realizations hit all across the board. And Isobel realizes that its happening again. Liz now understands what really happened to her sister and she hates Max for it. But what of Isobel’s blackouts. Who will she target next? If she killed once, she could kill again. The alien kids don’t know anything about their planet or people. They don’t know why they are there on earth but one thing is certain. Killing for them is too easy.