Mermaids and humans join forces in a radical plan to stop the oil company, but their efforts have a devastating effect. And facing an uncertain future, Ben, Maddie and Ryn…

Ben, Maddie and the other humans deal with the fallout from the attack on the oil rig, while the mermaids reacclimate to their ocean home. Ryn comes back to land…

The team must battle the French, Indians and Mother Nature after Flynn sabotages the Lifeboat and traps them back in Western Pennsylvania circa 1754.

A reporter seeks revenge when he discovers Lucifer has been sleeping with his estranged wife; a serial killer from Lucifer’s past resurfaces.

Lex tasks Supergirl with protecting Andrea from an anti-tech extremist, but his nefarious purpose goes beyond merely keeping Andrea alive. Meanwhile, Lena moves forward with Non Nocere, with Lex’s help.

The Brakebills students struggle to deal with the aftermath of a catastrophe that befalls the university. Back in Brooklyn, Julia makes her first foray into the mysterious world of Hedge…

Alice ends up risking everything to discover the truth behind her brother’s disappearance. Quentin and Julia are involved in a volatile reunion.

The students each deal with a personal matter that keeps them from focusing on the upcoming Welter’s Tournament.

Diggle and Felicity are shocked by Oliver’s decision to ask the Bratva for help in taking down Prometheus.

Oliver, Team Arrow, ARGUS and the SCPD kick off a citywide manhunt for Adrian Chase. Helix tells Felicity they have a way to find Chase but they will need something…

Peter’s visit to the other side intensifies as the alternate FRINGE division faces off against a formidable new foe in a harrowing race against time.

While on the haunted house ride at Santa Barbara’s Scare Fest, Shawn and Gus witness a murder and are soon led to believe the person who committed it is the…