Two young mermaids, Ondina and Mimmi, run away from the Mako Island pod with Sirena to try to turn the merman Zac back into a land boy. But Zac's connection to Mako is growing stronger. If they fail, ...

The chamber's true purpose is revealed: to drain the magic from all mermaids. Zac risks his life to shut it down and restore the mermaids' magic.

Time to mark a legend-ary occasion—March 29 is International Mermaid Day! Apparently, the cable network Freeform founded the annual holiday in 2017 to celebrate the launch of its TV show Siren. The ...

Cam shows Nixie that he is hiding the trident in his school locker. Evie agrees to keep everyone's secret until after Zac is turned back into a normal human. Cam apologizes to Zac for betraying him.