After the Nihilanths defeat, a group of remaining Black Mesa scientists have been extracted by a co-officiary of the administrator. Gordon Freeman has been dispatched back into Black Mesa alongside a rescue team to find and extract Eli Vance. This was originally created by Legacy (Legs, Sir-Tuc, Pelot).
Welcome back. Kill... your future depends on it. Eli Vance has to be found. I wonder why the adminstrator wants him.