FREEFORM | 8:00 pm

While the mermaids get re-acclimated to their sea home, Ben, Maddie (Alex Roe, Fola Evans-Akingbola) and the other humans grapple with fallout from the attack on the oil rig in "No North Star," the summer premiere. Ryn (Eline Powell) returns to land to honor an agreement with the military, although their objectives are murky.