She leaves the guy at the bar. He doesn't even notice because another chick immediately takes up her vacated seat.

Carrying her glass of water, Elsa skirts the edges of the dance floor, keeping an eye out for familiar red – not that she's particularly successful. The floor is writhing, with few lights to help. Anna's wearing- wearing a green spaghetti-strap top and jeans. Elsa's eyes rove over the crowd, her heart sinking for each moment she can't see Anna.

It's not- she wouldn't leave, not without Elsa. So where did she go?