One Late Night: Deadline continues the story of One Late Night, a horror/mystery game where you play the role of an office worker caught in the middle of the paranormal activity that has broken out in a seemingly ordinary office building. Freely explore the 5 story office complex that houses several different companies. Look for clues around the offices, read newspapers about local events, hack your colleagues emails – anything that might tell you something related to the strange happenings.
Go to: http://store.steampowered.com/ and download STEAM client
Click "Install Steam" (from the upper right corner)
Install and start application, login with your Account name and Password (create one if you don't have).
Please follow these instructions to activate a new retail purchase on Steam:
Launch Steam and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam...
Follow the onscreen instructions to complete the process.
After successful code verification go to the "MY GAMES" tab and start downloading.