Siren
Helen's Antiquities
Ryn runs out of the store after hearing the signal and later Maddie, Ben, and Ryn bring the new mermaid they saved to see Helen in episode 2x01 “The Arrival”. Viv and Eliza answer Cami's call and they walk off with her in episode 2x05 “Primal Instincts”.
Appears in 3 additional episodes.
Serenity
Beth is leaving after talking to Helen when she sees Levi walking past and realizes what he is.
New World Order
Ben finds Helen's shop boarded up and covered with anti-mermaid graffiti.