Ben struggles with the siren's song effects, but Ryn also struggles with her feelings for him and Maddie, too.
Ben's struggling with Ryn's siren song, as she also struggles to hold onto power amongst her people.
Ben struggles with the siren's song. Xander finds out about the merpeople on land.
More of Ryn's people come to the shores. But something's forcing them there.
The merfolk have a civil war between their hierarchy on land, involving everybody in Bristol Cove.
Bristol Cove mourns, as Xander discovers the truth about Ryn.
Ben works with his Ted, to find info from the inside. Maddie gets to know Elaine better. Chris returns to Bristol Cove.
The longer Ryn is out of the water, the more she deteriorates. At the military compound, the other mermaid causes chaos.
Maddie and Ben try to help Ryn, as well as study her. Xander tracks down a lead on Chris, who's still locked up in the military's lab.
Ben tries to help Ryn, but the mermaid is only concerned with finding her sister again.
Bristol Cove - a town already obsessed with mermaids - is thrown into disarray after a mysterious young woman turns up.