Primeval - Season 4 Episode 3 -

A mysterious group come through an anomaly in a theatre, unknowingly followed by deadly tree creatures. As they attempt to escape, Matt inadvertently brings one of the group – Emily - back against her will. She promises to help him find the creature, in return for going back through the anomaly. In a frantic chase through the city, they track the creature down, only to discover the anomaly has closed, leaving Emily stranded.