At the beginning of your epic adventure, a mercenary task takes you to the far north – but you're also following up a mysterious lead at the same time – the first clue you've been given since Kyra's disappearance. You get a shock during a meeting with the delegates of a dark Brotherhood – your sister's kidnappers are indeed after your family's relict. Whether there's any truth in your family being chosen ones or not, the others obviously believe it – and if you ever want to see Kyra alive again, you'll have to act swiftly…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.