Siren fans have seen that Ryn and Donna have an incredible connection. But since coming to land, their relationship has come close to the breaking point. Check out the GIFs below to recap everything we know about the mermaid sisters, then have your say on their relationship in our poll.
Ryn's bond with her sister has always been special.
When her mother died, Donna looked after Ryn.
And the reason she came onto land in the first place was to save Donna.
Being out of water for so long almost killed her, but she couldn't bear to abandon her sister.
But living with humans has changed something about Ryn.
She has developed a strong emotional bond with Ben and Maddie.
When the sisters found each other, they returned to the sea together.
Ben and Maddie weren't sure if they'd ever see them again.
But they had to come back to Bristol Cove when their food ran out.
The government was overfishing to starve the mermaids to the surface.
Ryn knew Ben and Maddie would help them.
It was her idea to come to land -- Donna was very hesitant.
But Donna didn't trust the humans, and attacked Ben.
After her experience in the lab, Donna saw all humans as threats.
She couldn't understand why Ryn had protected Ben and Maddie.
And Ryn revealed that she'd never fought with her sister before.
Later, the two sisters reconciled.
Even after all the fighting, their love was stronger than ever.
And Donna showed Ryn what the scientists had done to her.
For the first time, Ryn understood the pain Donna had gone through.
Ryn agreed to help hunt the men responsible for Donna's suffering.
Her predatory instincts kicked in.
But Ben and Maddie arrived just in time to save Decker's life.
Ryn was hurt that Ben had helped Decker, and she fled with her sister.
Ryn tried to explain to her sister that not all humans were evil.
She would never hurt Ben or Maddie.
But Donna couldn't get over the rage of being betrayed again.
Her anger overpowered the love she has for her sister.
And she returned to the sea, leaving Ryn alone on land.
After all they've been through together, it was heartbreaking to see them leave each other.
Do you think Ryn and Donna's relationship can ever be repaired?
Let us know how you voted in the comments below!
And remember, you can watch all the latest episodes of Siren right now on Freeform.