Nicky and Henry follow a lead involving a professor who may be able to help in their search for Zhilan. Meanwhile, as Althea’s past comes back to haunt her, a…

Charlie and Rex sniff out the suspects when the Chief Superintendent of the St. John’s Police Department dies at a popular restaurant and all signs point to poison.

Charlie and Rex sniff out the suspects when the Chief Superintendent of the St. John’s Police Department dies at a popular restaurant and all signs point to poison.

A young couple are gifted everything they could ever wish for… but there’s a catch. Then, an aspiring comic artist keeps hitting roadblocks. As she doodles away her frustrations, she…

Ben and Maddie help Ryn guide her surrogate though a life-threatening delivery. Helen and Xander deliver a hybrid corpse to Beth at The Ranch. Xander faces danger on the high…

Ryn returns to land to explore human motherhood. Maddie and Robb come across a gruesome discovery. Ben experiences mysterious side effects and Ted confronts Helen.

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…

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…

As an old friend visits Helen, a new mermaid arrives leaving Ryn questioning their motives. Maddie learns the truth behind Ian’s death, as Ben fights for his mother’s treatments. While…

When another mysterious death is uncovered in Bristol Cove, Ryn suspects Tia. Maddie befriends a new acquaintance in Seattle. Helen warns the hybrids of trouble. Xander begins training and Ted…

When Ryn is taken in for questioning, Maddie rushes to her rescue. Meanwhile, Ben and Xander return to the deep sea to search for answers, only to be met by…

Bristol Cove mourns a loss causing Ryn to experience a new human emotion.

In the season finale, the enchanting siren song takes hold of Ben and Decker. Meanwhile, Dale must answer for the escalating crime in Bristol Cove.

When the military facility goes on high alert, Chris manages to escape, but he’s not the only one who gets out.

Mermaid mating season has begun, with Ryn knowing she will need to go back to the sea to help her colony. The hybrids convince one of the mermaids to come…

Ben begins to investigate some suspicious overfishing, meanwhile Decker ramps up his efforts to find his escaped mermaid and shows the true extent of his influence.

Ben and Xander are left dealing with a shocking discovery about Chris and his connection to the military. Meanwhile, Helen and Maddie reluctantly seek help from the hybrids as the…

Ben faces a choice that has rippling consequences amongst mermaid, hybrid and human alike, as the truth about mermaids is exposed.

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 coastal town of Bristol Cove, once known for being home to mermaids, is turned upside down with the arrival of a mysterious girl.

With Elaine Pownall’s health worsening, she seeks treatment from the military’s medical trial using mermaid cells, but the procedure doesn’t come without side effects to the mermaids. Meanwhile, Helen and…

Ben and crew of The North Star uncover a device emitting a strange sound. Meanwhile, Ryn finds shelter in the home of the local folklore expert.

Dale and the local police’s investigation starts pointing directly to Ryn, meanwhile Xander and Calvin’s search for Chris heats up when they locate the nurse who works at the military…

Ryn goes back to the ocean to get help for Ben and Maddie’s conditions but discovers that continuing to go back may get harder than she realized the longer she’s…

Ryn decides they need to find another solution for housing the mermaids, as hiding them becomes increasingly difficult. Ben becomes a mentor to Levi as he tries to learn how…

Ryn continues to try to teach the other mermaids to be more human in order to better assimilate, but some are starting to resist her, causing Ryn to wonder if…

Dale copes with the fallout from Maddie and Ryn’s encounter with the man from Susan’s past, while Katrina continues to persuade the rest of the mermaid pack to get on…

Tensions are rising following a shocking discovery. And living in a tank rather than the ocean is starting to have an adverse effect on many of the mermaids. Hoping to…

With more mermaids landing at Bristol Cove’s shores, the threat of discovery increases. After his encounter with the siren song, Ben tries to cope with the after effects. Maddie’s mom…

Ben, Maddie and Ryn desperately try and keep the newly arrived mermaid pack hidden from the rest of the town, but the new mermaids’ quick degradation on land forces them…

The team tackles their primary mission: stop a cataclysmic event that could change the course of human history.

Dr. Jared Kalu makes a surprise return to San Jose’s St. Bonaventure Hospital with his billionaire patient. Meanwhile, Park must treat the man his wife had an affair with and…

When an alien attacks National City, Supergirl and the DEO learn the alien is a Phorian, an otherwise peaceful race with telekinetic powers. Guardian gets a lead on the Phorian’s…

Supergirl grapples with whether or not to obey the President’s orders regarding Rhea’s latest actions. Meanwhile, Cat Grant returns to National City.

Supergirl challenges Rhea to battle to save National City. Meanwhile, Superman returns and Cat Grant offers Supergirl some sage advice.

Armek, a White Martian, descends on National City intent on taking M’gann back to Mars to face her punishment as a traitor. Hank and Supergirl determine the best way to…

Alex is kidnapped and the kidnapper threatens to kill her unless Supergirl releases a notorious criminal from prison. Supergirl and Maggie have always had different approaches to apprehending criminals but…

Supergirl learns the true depth of Serena’s nefarious plans for Earth. Supergirl, Mon-El and Alura must devise a plan to stop her before Serena gets to Earth. J’onn prepares to…

Myr’nn inadvertently causes psychic disturbances at the DEO; Supergirl must work with J’onn to contain the chaos; Mon-El begins training Kara in fighting techniques he’s learned in the future.