Valve announces a brand new single player Mutation, called Last Man On Earth, is available this week to owners of Left 4 Dead 2 (L4D2) "The Passing" DLC. 

Last Man On Earth, mixes up the award winning multiplayer gameplay for a more solitary pursuit, removing the co-op aspect and instead a sole Survivor with no bot companions is pitted against an army of Special Infected.

The L4D2 team is encouraging players to submit their best 60-second clip of playing Last Man on Earth to YouTube so everyone can share in their single player accomplishments.

If you still crave company, all other game modes are always available including the recently unveiled Realism Versus. 

Weekly Mutations are available to all owners of "The Passing" DLC on PC and Xbox 360.  Each week a brand new Mutation is made available.