The museum features several exhibitions. The first one is the military exhitibion, which features tanks, aircrafts and weapons, many of them from Postal 2, including the Thermo-nuclear warhead. The second exhibition is the prehistoric exhibition, which features a group of mammoths fights a group of t-rexes. The third exhibition is an arts exhibition, consisting in a group of paintings and sculptures. Then comes a playground and finally the exhibition where the Holy Water that Jesus used to resurrect Lazarus is shown.
When John arrives to the museum, he finds himself trapped inside since the doors are locked, and also discovers a zombie eating a dying man's body. After that, he is tasked with destroying 100 zombies. The museum introduces a new type of zombie: the plastinated zombies, which are taller, tougher zombies that resemble the real-world plastinates from the Body Worlds exhibition. Once he completed this mission, a door in the lobby opens. When John enters, he is confronted by the Skeleton Boss, a huge, winged skeleton that throws dynamite. After eliminating the boss, a drain in the engine room opens. This drain leads to the Sewers.
As revealed at the end of the game, Lorie was possessed, so when she suggested John to hide at the museum, she intended him to die at the hands of the zombies. Lorie also cursed the Holy Water so that everyone that touched it was turned into a zombie.
- At the lobby of the museum, a sign displays the entrance cost to the exhibitions. Children must pay $3, adults $5, zombies $100 and quadropalegics enter for free.