Members - Half-Life : Alpha Operation mod for Half-Life

The same phenomenon is going on. Gordon Freeman wakes up in unfamiliar places. Black Mesa to go to the underground center is its unique mission. To go there is to go to the Black Mesa entry bridge. Underground portal is said to exist. Xen built a center on the planet, and soon was destroyed by monsters there. And staying fit as a fiddle of gold there is a crystal. And unknown to him what will be reached.