Siren (television) Hour long drama series on Freeform, debuting on Mar. 29, 2018. A mysterious and otherworldly girl is wreaking havoc in Bristol Cove, a sleepy coastal town that legends say was once home to mermaids. Marine biologists Ben and Maddie must work together to find out who she is and what she wants. Could she be a mermaid, a primal hunter of the deep sea driven to land? And, if so, are there more out there? Stars Eline Powell (Ryn), Alex Roe (Ben), Fola Evans-Akingbola (Maddie), Ian Verdun (Xander), Rena Owen (Helen).