Siren 6/20 on Freeform

"All In" 8PM ET - 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 Rick learn more about the hybrid status, their history in Bristol Cove, and discover they are far less alone than Helen once believed.