The original mod version, which includes everything up until the "Xen" chapters, is available for free. You can find it on ModDB or The Valve Developer Community . This version requires the Source SDK Base 2007 (free on Steam) to run.
An experiment goes wrong, tearing a hole in space-time and allowing hostile aliens to teleport into the facility. Black Mesa PC Download Free Torrent
Updated graphics, expanded environments, and a completely rebuilt ending (Xen). ⚠️ Security and Legal Warning The original mod version, which includes everything up