With news of one last sinkhole opening, Gavin, Izzy and Dr. Nathan race to Seattle to launch a final rescue effort before it's too late. Eve embarks on a perilous journey to send a young boy though a portal in order to save her family.
A reunited Harris family leads the effort to rescue Caroline and stop the sinkholes from happening, only to face forces that threaten to tear their family apart. With Lucas' life on the line, Ty accepts a challenge to win his friend a cure.
