The episode starts with Madney's live rehearsal for the concert taking place later that day. On live television, Madney loses her voice, but it becomes clear to the Alpha Team that a spell had been cast. After researching the spell and the missing Semchanach from Otherworld, the Team discovers that a mute siren named Aquaphonis stole Madney's voice.

Tara is forced to audition for "Big Star" with a spell that made her voice better. To complicate matters further, obsessed wildlife specialist Henry Delachasse is also hot on the pretty mermaid’s tail, determined to make her the latest addition to his collection. Fortunately, Tara, Cal and Sparrow have boundless imagination and more than one trick up their sleeves…