Obsidian Entertainment’s espionage RPG Alpha Protocol is now available for pre-purchase through digital games store Steam and to encourage you to buy, Steam is offering another RPG for free.

The freebie in question is Gas Powered Games’ Space Siege. It’s a sci-fi action RPG that was billed as a spiritual successor to Dungeon Siege. SS and AP are both published by Sega.

If you pre-purchase Alpha Protocol, you’ll be able to download and play Space Siege immediately.