Ryn returns to Ben and Maddie. The thrupple must learn to trust an outsider.
Ben and the mermaid enact a plan to ruin the oil company's plans. But nothing goes as expected.
After Sean's body washes up in a fishing net, things get sketchy for Ben, Sheriff Bishop, and Xander.
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.