That’s right, from 12:01 AM on October 31 to 3:00 AM on November 1 anyone playing mutiplayer games may randomly get an “Infection” game. Infection gameplay is simple: one person starts as a zombie, and as he kills people, gains more and more zombies to slaughter the remaining players. You know, like how it is when zombies attack. How awesome is that? Totally.
I played this mode yesterday with the famous GMoney and it was really fun. It gets better with more and more people, all huddled in one room scared for their lives. This is a limited time offer, however (of course you can still play it in custom games whenever you want). Bungie had this to say:
Infection is a lot of fun when everyone is into it, but we don’t think it would make a good playlist long term, so it’s going to come and go. [But] if everyone has a good time, who knows? It may return, as the restless dead are known to do.