FREEFORM | 9:00 pm

This spooky fantasy — Freeform's most-watched series last year — returns for Season 3 with two back-to-back episodes that pick up the action shortly after the Season 2 cliffhanger, which saw Ben (Alex Roe) allowing a reporter to die to protect the secret of the mermaids and his other friends. As the story resumes, however, that fateful act sets off unforeseen ripple effects in his relationship with both Maddie and Ryn (Fola Evans-Akingbola, Eline Powell). Meanwhile, a dangerous new mermaid arrives and challenges Ryn's leadership.