The story begins when the Five are told their is another 6th unit who they've never met- Clark. But seconds later, Iris is found dead.
Hera becomes suspicious of Rhea and Eros because they're being secretive about their whereabouts the night of the murder. She quickly susses out that Rhea is covering for Eros and goes to the authorities who've hired an intense detective (Orsino) to handle the investigation. Her judgement is clouded because she believes Eros was having an affair with Iris and that triggers her own memories of Apollo’s infidelity.
Persephone decides to take advantage of the situation by posting grief-stricken blog posts, finally bringing positive public attention to her.
Iris' funeral is interrupted by a terrorist group, The Void, who stage a very public stunt that frightens everyone.
In the chaos, no one has noticed the arrival of Clark (the 6th unit) who has been sent to wait at Rhea's house. He and Rhea meet and neither are immediately impressed with each other.
Eros is arrested for Iris' murder and this is when Rhea learns that he and Iris were having an affair of their own. She is especially hurt because it seems everyone besides Rhea was aware of it. The government basically decided Eros and Iris had the best chance of making a baby and Eros didn’t want Rhea to find that out and get hurt, so he went along with the secret sessions.
Rhea, furious, throws Eros under the bus and decides to skip town... but... She's interrupted by Clark and has to take him with her, in case he tells anyone where she’s going. Rhea pretends they’re going to a safe house.
Persephone sees them leaving but decides not to say anything because she's pretty happy right now. The President is actually into her little diary project and asks her to use it to spread incriminating info about Eros.
Rhea leaving FREAKS Hera out. She's so shaken she goes to talk to Eros to see if he knows where Rhea might have gone. But Eros refuses to help.
Rhea and Clark's road trip is interrupted when Rhea crashes their car. They have an angry few hours when Clark tries to convince them to go back- this is when he learns Rhea has been lying about the safe house and he actually worries that maybe she’s on the run because she killed Iris. The two are rescued by the scary terrorist group, The Void.
BACK AT HOME
Persephone finds out the president and the detective are arguing. They disagree on who killed Iris. President Black asks Pers to help her incriminate Rhea. She, Hera, and Charon walk together outside when gunfire rings out. Persephone's chaperone/lover, Dion, is killed.
BACK TO RHEA AND CLARK
They're sort of being held hostage but having fun. Rhea finds out the leader of the terrorists, Rebekah, was her surrogate mother. Rhea actually kind of likes and respects Rebekah, who fills her in about her organization. They want to upset the status quo and they have a spy on the inside. She and Clark finally start getting friendlier.
BACK AT HOME
Dion's death frightens everyone. Hera is even less stable than before. Apollo comforts her and she lets him. She thinks a lot about the past and how scary the future is, she decides that maybe she should let herself have what she want. And that’s to forgive Apollo.
Persephone is ANGRY. Lashing out. Char tries to talk to her and that's when it comes out Char is the spy for The Void. The person who was supposed to be assassinated wasn't Dion, it was him.
Char says the Void made him feel special and that he kind of believed in what they were doing- but when they wanted him to blackmail the president he chickened out and ditched them. Char tries to appeal to what he and Persephone have in common; that they've never felt as important as Rhea, Iris, and Eros. But Persephone isn't having it.
She goes to Hera with the blackmail info and Hera assumes the president is the one who actually killed Iris. By this point, Hera and Apollo are fully back together. Persephone thinks this is a bad idea, but she’s also worried about Hera’s mental state. Hera hasn't slept in 4 days. The last time she went on one of these insomnia streaks was after she lost the baby and she had a mental breakdown and stabbed herself in the uterus.
BACK TO RHEA AND CLARK
They’re starting to understand each other, and Rhea is trying to make Clark feel less freaked out and safe. They get a little tipsy and make out but Rhea panics. Tries to wonder why she can't just be friends with him. Feels guilty about Eros, who she knows must be going through hell. She runs outside and into Rebekah who lets her in on a secret- the information Black is desperate to keep secret is that Hera was NEVER pregnant. It was a publicity stunt.
Rhea is now angry and ready to bring the president DOWN. Rebekah gives her a flash drive with all the evidence of her big lie and Rhea and Clark head back home in secret. However, when they arrive they are ambushed by Orsino. Apparently he and Rebekah have teamed up against the President and Rebekah was only delivering Rhea back. A trap.
Rhea and Clark are taken to jail where they meet back up with the other Five. Char is feeling terrible about Dion. Persephone is furious. Eros is really angry with Rhea. Now that they're all in the same room though, they start pooling info and figure out the murderer must be...
Hera finds these voice messages on Apollo's phone from Iris putting him at the scene of the crime. Apollo drugs Hera an incapacitates her.
We then get a scene where Apollo explains what happened. Basically, Apollo thought if HE could impregnate Iris he could impress Hera and they could get back together. But he and Iris got in a fight and he snapped and killed her.
The Five band together to break out of prison and Rhea runs home to Hera but has to fight Apollo. Hera and Rhea escape. Rhea decides not to tell Hera she's never been pregnant because it would destroy her.
Persephone finds out she's pregnant and now the whole world is overjoyed. Rebekah tells Persephone that if she doesn't want to end up a lab rat she's got to play by her rules. Because Dion is dead, Rebekah wants to say Apollo is the baby daddy. Persephone agrees and now everyone hates everyone.
It’s been about three months since the events of season 1 and although on the macro, everyone is really happy and hopeful about the baby- things for the Five themselves are not great.
Rhea desperately wants to reconnect with Eros, but he’s ignoring her. Except when they need to cop. Which is more than ever because everyone is so incensed by Persephone’s success.
Hera has channeled all of her rage into getting stronger, but she’s not sure how to help her sister AND she is still having to see Apollo on a daily basis.
Persephone feels lonely and bored. She’s not allowed to do anything but lie around and wait to have the baby. Unless she needs to do publicity work with Apollo, who loves being celebrated for doing nothing. This only serves to remind Persephone of Dion. To distract herself, she decides to make a project out of Clark’s obvious crush on Rhea.
Not that he’s willing to admit that to anyone, especially himself. The two have become very good friends, and that’s clearly all Rhea wants.
Charon is struggling with his fear of being killed by Rebekah. He is always on the verge of descending into paranoia, but his best friend Eros is too busy trying to keep himself together to be much help. He still feels wracked with guilt over Iris’ death.
Things change when Clark’s new chaperone, Talc, is introduced. Feeble and blind, Talc is from one of generations that was over-experimented on before they were born.
Rebekah announces to the Five and their chaperones that she is sending them North to Canada to do a press tour to rally spirits. Everyone is dubious, but have little choice as Rebekah has replaced Black as president.
On the train, everyone is basically on top of each other. They are bickering and insulting each other. And they are also really nervous about the presence of Rebekah, who has planted the idea that Rhea is hiding something in Hera’s head.
When Hera starts to ask Rhea about this, she panics- thinking she’s going to have to finally tell Hera she was never pregnant. Rhea retreats with Clark, emboldened by his “tutoring” sessions with Persephone. The two go on a little adventure exploring the train and stumble upon Apollo, beaten within an inch of his life.
From Apollo’s perspective, we learn that he isn’t quite as happy as he seems. No matter what he does, it still seems like the only people anyone cares about are the Five. He hates being around Hera when she’s mean to him. He hates how mean Persephone is to him. He can’t understand why people won’t give him even a little sympathy. Yes he killed Iris. But it was an accident. Kind of.
In his cabin on the train he finds a mysterious message that leads him to the kitchen, where he finds a bag containing confidential information on The Five. The rest of his day features a series of suspicious interactions with Rhea, Eros, Talc, and Hera. It quickly becomes clear it isn’t a question of “Who would want to kill Apollo?” but who wouldn’t?
As the train approaches its first checkpoint the remaining passengers are faced with a question, do they tell someone about Apollo and get him help? Or do they let him die?
Rhea and Eros are firmly in the “let him die” camp, mostly because they think no matter who did this to him, Hera will get blamed for it because she isn’t as valuable as the rest of them. Hera on the other hand, wants Apollo to get help. If they kill him, then they are just as bad as him. Right?
Charon is too preoccupied with his own little scheme, actually working with Rebekah to test out an experimental new medicine. In his thinking, she can’t try and kill him if he makes himself valuable.
Persephone is undecided, as is Clark. Until Rhea and he finally have sex. Then he’s pretty much on her side about everything- which is what Talc tries to warn him about. But he won’t listen.
When they reach the checkpoint, Talc helps Hera make a break for it, but as she runs to try and find someone to help she realizes there’s no one at the station. Where is Rebekah taking them?
Rhea and Eros chase her, but are apprehended by Rebekah’s two security guards and Orsino. Who was the real reason they stopped; they needed to pick him up.
He is just as awful as everyone remembered, and the sight of him is triggering PTSD-like symptoms in Eros.
Rhea and Hera have a fight about why Apollo is even worth saving, which leads Rhea to finally tell Hera the truth; she was never pregnant. Hera is crushed and Rhea feels like a monster.
Rhea and Eros finally air all their grievances. And end up having sex. Mostly out of desperation to just feel like themselves.
Char is privately struggling with the knowledge that he knows he was somehow involved with what happened to Apollo. The injection Rebekah gave him made him disoriented and bad at controlling his emotions. He was in the kitchen car when Apollo came in, holding the file about Char’s own medical history. He told Char he was non viable, which caused him to panic. If Rebekah found out Char was non viable she could really easily get rid of him. Char tried to take the file from Apollo, but Apollo fell and cracked open his head. But when they found Apollo he was beaten much, much worse. So who did that?
Persephone is really upset with Rhea on behalf of Clark, but the two decide to strategize about how to take over the train anyway. Char handles Rebekah while Pers distracts the security guards. Rhea tells Orsino she’s going to confess to beating up Apollo, but she instead lures him into the caboose. All they want is to lock him in there with the guards and unhook the car from the rest of the train, but a scuffle ensues and Eros ends up hurling Orsino over the railing. Orsino is killed before the train car is detached.
The Units don’t have much time to enjoy their partial victory though, because Persephone is bleeding.
Rhea tries to get Hera to help with the baby emergency, but Hera is alternating between angry and catatonic. She reluctantly agrees to help.
Clark wants to talk to Rhea, but she’s so desperate to avoid him she goes and sees Rebekah, who refuses to help them get home. Her paranoia-induced plan was to restart with the Five somewhere else. They are interrupted by the sight of another train- stopped on tracks parallel to their own.
Eros and Clark volunteer to venture out into the snowy tundra to see if the other train is safe. Once on the train though, they get into a fight over Rhea. Clark learns that Eros is fine with her sleeping with both of them, because Eros just really wants Rhea to get pregnant. Their fight only lasts a few moments though, as they are soon attacked by wolves.
Back on the other train, Rhea and Persephone have a heart to heart. Finally burying the hatchet. Rhea also goes to speak with Hera because after seeing what Eros was capable of doing to Orsino, she knows it must have been him who beat Apollo.
Hera doesn’t care much about Rhea’s discovery. She just wants to be left alone. But when it becomes clear Clark and Eros have been gone too long, she steps up to help Rhea search for them.
Still trapped Eros tells Clark about what happened with Apollo, it was Eros who beat him. He had found him injured in the kitchen and tried to help him. But Apollo started talking about something else he’d learned from his little files; if Rhea couldn’t conceive soon, she was going to be placed in a medically induced coma so she would be easier to handle. The news scared and shocked Eros, who tried to quiet Apollo who just started taunting him. Eros slipped into a Post Traumatic episode and started hitting Apollo.
Rhea and Hera enter the train car only to be attacked by the wolves that cornered Eros and Clark. Eros comes to their rescue. But is dismayed when Rhea assumes Clark isn’t with him because Eros hurt him. Clark has actually just snuck out through a ceiling window on the train and had run back for help.
As they transfer between trains, Hera asks herself if she really wants Apollo to survive. He’ll never be the same if he lives. He’ll just be someone else she needs to take care of. She decides to smother and leave him. Everyone else assumes he’s died of his injuries.
When they finally arrive back in Minneapolis, Hera moves out of Rhea’s house. She needs to be on her own. Clark is “Dumped” by Rhea, but not so she can be with Eros- so she can be alone. She hates how she treats people and knows she needs to change. But she’s gotta be on her own to do that. Clark is hurt, but Talc swoops in to ask if he wants to help him change things. It was Talc that put that bag in Apollo’s hands. Because Talc believes the Five need to be in control of their own fate.
Charon is non viable and he knows he’s going to be sent away. But Persephone, feeling benevolent, decides that Char should be her new chaperone. So he can stay with his friends. Persephone’s baby is fine, and she’s a girl. She is nervous for her daughter’s future.
Rhea learns from Rebekah that she herself is pregnant. She doesn’t know if it’s Clark or Eros’, but she doesn’t care. She knows who this baby really belongs to. She runs to Hera to tell her the news and the two have a teary reunion.