Mako: Island of Secrets (2013)

S1E8 Zac's Return to Mako

On a full moon night, the mermaids devise a plan to prevent Zac from gaining power by keeping him away from the moonlight. Believing that this will revert him back to his human form, they decide to stay with him in his garage throughout the evening. Their mission is to ensure he remains indoors, hoping to thwart any potential transformation and protect their secret.