Dead zone is the new (and first, lol) mod from Deadmouse-Studios, its a three way competition between the (optimistic as ever) "survivors", the austere and mysterious S.P.E.C.T.R.E (led by the even more mysterious NEXUS) and the ravenous horde, a large group of zombies banded together under the banner of the "OVERLORD".
Great song made by Sculpted-cold from Newgrounds.
Download the song: Newgrounds.com