Ben and the mermaid enact a plan to ruin the oil company's plans. But nothing goes as expected.
Ryn deals with guilt over what she's done while Ben discovers new information about his father's relationship to Big Oil
Katrina is fighting to take back the merclan, while Ryn is helping Maddie fight for her mother Susan's safety.
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.
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.
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.