Half-Life: Edge of Darkness

After proving your skill and cunning by escaping the Black Mesa complex alive, you have been called on by a shadowy organization – the Alien Counter-Insurgency Bureau – to help protect mankind from the threat posed by Xen. Tonight, the A.C.I.B. has need of your special abilities to counter a new threat to civilization. You have been given a rendezvous in the warehouse district of the city to receive your mission briefing.