Ryn, Ben and Maddie must protect Bristol Cove from Tia’s army. Meanwhile, Ben’s injections are producing unexpected results, which alarms both him and the others. Xander juggles best man duties…

Ryn, Ben, Maddie must recruit new allies in the fight against Tia. Helen seeks answers when she’s haunted by Donna’s spirit. Tia obtains dangerous weapons she plans to use in…

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…