George Romero’s third zombie film was originally planned to be much more epic than what was eventually filmed.

What was made is still good but nowhere near as good as his previous two films.
The zombie outbreak has ravaged the world and the human race is barely surviving. A small group of scientists are trying to find out what caused the zombie virus and are searching for a remedy. The army soldiers that have been assigned to protect them are tired and burned out.
Dr. Logan (Richard Liberty) has been experimenting with the zombies. Instead of finding a cure he decides that zombies can be domesticated. He has managed to tame one zombie named Bub (Sherman Howard).
Naturally things fall apart. This was one of Romero’s weakest entry in his zombie movies. But after watching it a couple of times over the years it holds up pretty good.