Ryn discovers a refuge of injured mermaids that escaped Tia's violent takeover. Ben and Xander get caught in a battle with Tia's troops. Maddie feeds Robb half-truths to secure his discretion. Ted explores his family lineage.
- Ben documents that he has taken 5 injections of the mermaid stem cells at this point, he has recently taken another two doses. He will make more extractions.
- Another effect from the stem cells is increased hearing, this is demonstrated when he stops by to get a latte and hears the conversations of other patrons in the coffee shop. It is also the reason he was able to slay one of Tia's merman warriors while on the island.
- Calvin is shopping for a suit to wear on his wedding day. Xander helps him build confidence for when he delivers his vows to Janine.
- Xander is going to be the best man at Calvin's wedding.
- Ted Pownell goes to Bristol Cove City Hall where he finds records of Rick Marzdan, on his way out he bumps into Xander. Ted is glad that Xander is enlisted at the police academy, but repels his statement about how not all mermaids are bad despite meeting Ryn in "Mixed Signals."
- Rick tells Beth that he informed Ted Pownell about the location of Caspian Ranch believing it was the right thing to do. Near the end of the episode, Beth unloads a truckload of necessities. She and the hybrids do not trust Ted and will keep a watchful eye on him when he sets foot on the ranch.
- These neccesities include: drones, surveillance cameras, and firearms.
- Maddie learns of Ben's self-experiment in this episode.
- Xander shoots the assailant merman that was about to kill Cami, afterwards she tells him that they are good. This means that Cami has completely forgiven Xander for killing her mother Donna.
- Judging by what Ryn said, there is almost no one in their colony who was spared by Tia's takeover.
- Ryn offers Katrina the chance to return to her tribe, and rather than accepting she uses Ryn's spear to slice her own neck causing her to die from a severe loss of blood.
- Hunter is believed to be deceased at first, but reveals to have survived from her injuries. Later, she is questioned by Tia and reveals the existence of Ryn's baby to her.
- Now that Tia knows about Hope, she along with Levi and Mate are going to be in serious danger.
- Maddie takes Robb to the same cave that Helen took Ryn's tribe to in the episode "Entrapment" where he learns of the peace between mer-people and humans. At the end of the episode, Maddie brings Robb to the apartment, Ryn attacks him claiming he is a merman from another tribe. Robb admits that he is.
- This episode marks Ben's first kill. While Ben letting Ian drown caused the latter's death, the battle on the island marks his first direct kill.
|“||As of now I have given myself five injections. My cardiovascular endurance has improved. As of this morning, I can hold my breath underwater for 10 minutes. My lung capacity seems to have increased, as it did with my mother. Today I doubled my dosage. The current batch of stem cells is depleted. I'll need to extract more from the specimen. Once I have, I will continue to log all my changes.||”|
|— Ben documenting his recent video journal.|
|“||Just because they look like us, doesn't mean they're like us. It's a mistake to trust them, you know that more than anyone.||”|
|— Ted to Xander.|
|“||Tia is getting stronger. More and more are joining her. Many from my waters are dead or injured. I'm afraid Ben.||”|
|— Ryn speaking to Ben about Tia.|
|“||You are too weak to be leader.... Too human.||”|
|— Katrina to Ryn|
|“||When you came to our tribe you were lost. We took you in. You became one of us... It doesn't have to end this way. You don't have to die.... You could come back... Let me help you.||”|
|— Ryn persuading Katrina to return to her tribe.|
|“||You bow your head to me, but does that mean I should trust you? Of course, you want to live, so you say you'll be loyal to me yet you fought for Ryn. So I ask again, why should I trust you?||”|
|— Tia to Hunter.|
|“||No one steps foot or off our ranch without our knowing. We keep ourselves safe. No one else is going to do it.||”|
|— Beth to Rick|
|“||It's true. I'm one of them.||”|
|— Robb admitting to Ben, Ryn, and Maddie that he is a merman.|