Four students are getting ready for a night out in Glasgow. That night a new friend joins the gang, called Helen. One of the guys, Tim, falls instantly in love with her while the leader of the pack, Julia, feels annoyed by Helen stealing the limelight. There is a mystery surrounding Helen and the scene ends with more questions raised about Helen rather than any answered. The students then move on to a karaoke bar where Helen demolishes one shot after another, as the rest of the group struggle to play catch up. Her drinking culminates in her draining the cocktail of one of the other students within seconds. This seems to bring Julia and Helen together, an odd respect forming between them, which sees the girls eventually performing a karaoke number together. However Julia is not ready to submit her leadership and under her orders the gang of five leave the pub in search of food. They buy some junk food, with Helen eating in general much more than everybody else. Julia feels challenged and commands the gang back to the flat for a drinking competition for one final attempt to out do the new arrival. Before long Julia has lost her own drinking game and in turn her status as the pack leader. We cut over to a lab at a university where the film ends with a twist, one which the audience will not have been looking for, but one which on reflection makes perfect sense.