Siren has returned for the second half of its second season. The hit Freeform drama has kept viewers on the edge of their seats each week with so many underwater adventures. The show revolves around biologists Ben and Maddie who discover Ryn, a Siren, living on land for the first time.

When we last saw the show, a plan was out in place for the Sirens to return to the water. Not only that, but their plan to stop the town oil company from contaminating the water went into action. Ultimately, the sirens completed the plan and the oil company was halted. However, the plan caused Xander’s boat to go up in flames. Xander survived, but one Siren didn’t make it. And it happened to be the male Siren who formed the biggest connection with Helen.

The sirens are safe back in the ocean – for now. But Ryn returned to land to be with the people she loves, Ben and Maddie. The three were happy to be reunited, until Ben’s mom ended up in the hospital. Now, Ryn has agreed to be studied by the military in an attempt to save Ben’s mom.

In tomorrow’s episode, Ben’s mom is getting worse. 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 her cousin Rick learn more about the hybrid status. They also learn about their history in Bristol Cove, and discover they are far less alone than Helen once believed.