Once Upon A Time season 4 premieres today, Sunday 28 September 8pm EP.

The season 4 premiere episode is titled A Tale Of Two Sisters, and the episode will mark the beginning of characters from Disney's Frozen appearing in the show.

Click here to watch the premiere episode Live stream Online

In the season premiere episode, a scared and confused Elsa finds herself in Storybrooke and, fearful of the intentions of its residents, creates a powerful snow monster for protection.

Robin Hood's wife, Marian, is back in the picture, leaving Regina to wonder if her "happily ever after" with the former thief has been completely destroyed. And she turns for help from an old friend, to rightfully claim what is hers.

While on their honeymoon, Mr Gold/Rumpelstiltskin finds an intriguing object that makes him question whether or not he should officially give Belle control over the dagger that makes him The Dark One.

After confronting their feelings for each other, Hook and Emma this season will officially go on a date. But in the short promo released, Emma is seen avoiding Hook, and captain confronts her.

Meanwhile, in Arendelle of the past, as Elsa's sister Anna's wedding to Kristoff nears, Anna discovers that their parents, who died during a violent storm while at sea, were on a quest to find the secret to containing Elsa's out-of-control ice powers. And against Elsa's wishes, Anna wants to finish their journey to find out what they were looking for.

Here are a few tweets on the premiere episode