Quite A Headful

The flames roar to life. Mission "Maimed and shamed, Zombies scatter without brains. Still lowdown rests, In the old abodes." Abode A secret undergroud facility contains information crucial to the cause of my employer. I must retrieve it. Intel Shamblers without heads are harmless and vice versa. I should take advantage of this fact given how in bits and pieces the zombies are likely to be.