The gripping expansion pack for DOOM 3 takes your even further into the the DOOM universe. Two years following the unexplained disaster on Mars, the UAC returns to the abandoned facility to investigate a mysterious beacon buried deep in the ruins of the ancient civilization.
Open the Steam client, login and locate the Games tab on the top menu. Click this and then select “Activate a Product on Steam…”
Enter your unique code that's displayed on the 'Orders' page of CDKeys.com and follow the prompts to activate.
Your game is now viewable in the “Library” tab and is available to download/install when you’re ready. You can find additional support for the Steam client here: https://help.steampowered.com/en/wizard/HelpWithSteam
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