Still in Vietnam but also in Cambodia
This volume also takes place during and just after the Vietnam War but a lot of the action takes place in Cambodia. As well as the zombie/ghoul element and fighting the Viet Cong, our protagonists have Frankenstein-type monsters to face, constructed by evil scientists.
3 stories inter-mingle and eventually come together to form the plot of the first chapters. The scene shifts to a zombie siege in Mississippi.
Easier to follow than Volume 3, this works quite well and the illustrations are clear if not hugely gory.
 - Mark Kidwell, Jeff Zornow, Jay Fotos)