Spanish horror sequel. Picking up the action 15 minutes after the point where the original 2007 film left off, the plot follows a medical officer and a SWAT team armed with video cameras as they enter the quarantined apartment building in an attempt to neutralise the situation. They are at first relieved to find that the mysterious and deadly virus appears to be carried in the blood and not in the air - but in order to 'cure' the infected blood they must first locate those who have become possessed...