Gina Cross and Colette Green, and is the only official co-operative entry to date. The only expansion (presumed) to be canonical, as Barney later reappears as a significant supporting character in Half-Life 2 and its following episodes.
Working to evacuate the facility following the accident, Barney's story examines the outbreak from a survivors perspective instead of combating the problem like Freeman, it's about getting out alive. Additionally, Shephard is the only protagonist whose fate still remains completely unknown. Notably fills in what happened in Black Mesa after Freeman takes the battle to Xen. Involved in a chopper crash and separated from his squadron, Shephard awakens as the Marines begin their evacuation.
