Desmond is a slacker who is always late. He works at a corporate office and factory for Ammotech, one of the world's leading weapons manufacturers. His boss, Adam Nusbaum, calls Desmond into his office to talk about a pending company merger to warn him that he needs to do better at work. It appears that some of his colleagues have already been let go. As a result, Desmond and others spend time planning what they will do next.
After attending a company seminar with his friend/crush Samantha, Desmond notices pallet loads of drinks being unpacked in a corridor. He gets called back to Adam's office where he finds that Adam has killed his coworker. Desmond flees after having the spelling and grammar in his report criticized and is chased by the entire department. Other colleagues start acting aggressive and are all drinking this new energy drink. When Desmond tries to ring for help, the switchboard refuses to allow him to call out without clearance from a supervisor due to company policy. Desmond sneaks upstairs, finds Samantha working and stops her from finishing her energy drink. However at this point she is already experiencing violent episodes and has to be restrained. Desmond's colleagues from accounting team up with the advertising department after killing the head of department Bob.
Desmond's friend Mourad finds them hiding in a cupboard with him not having drunk the energy drink. They try to get out of the building but additional security is triggered when they try and break an external window. They decide to act crazy and make it to the HR department where they find Edward. Desmond uses the tannoy system to pretend to be Adam in order to rescue Edward. The four of them create makeshift weapons, fight their way to CEO Franklin Gantts office and demand to know what has been put in the Zolt energy drinks. Franklin tells them that the drink was created to make staff more alert. But this first batch has been altered by a recently fired scientist who held a grudge and has turned the staff violent.
Adam demands that Franklin lift the security on the building so everyone can leave and his mob break into the office, killing Franklin and Edward and announcing that they all want to resign from the company. Adam leads his mob down to the ground level and lifts the security on the building using Franklins finger for identification. Meanwhile another colleague Nicholas admits that the drink was altered due to deadlines and having to 'make do' on the order. Nicholas says that there is an antidote and Desmond and Mourad head downstairs to get it to cure Samantha but are seen on CCTV. A fight ensues and they distract staff with additional Zolt energy drinks and Mourad takes some of the cure back to Samantha.
Adam fights Desmond who taunts him about how little work he has done during his time at the company and blows him to smithereens with a land mine. Mourad, Samantha and Desmond shoot the remaining violent employees and run out the front exit of the building. Samantha kisses Desmond telling him to not wait so long in future to make a move, and together they watch as emergency services arrive.
