Just had a really interesting dream, which I'm planning to turn into a story.
Here's the plot so far:
The protagonist moves, with her cat, to an apartment that allows pets. It turns out that most of the tenants have cats and let the cats wander freely throughout the building, so there are cats everywhere.
Some of the cats have one eye bigger than the other. They act just like all the other cats. Two of those cats, except for the eyes, look and act exactly like two of the protagonist's former cats, both of whom died recently. The protagonist knows they aren't her two cats, but pretends they are and is really friendly with them.
Then the protagonist and some friends go out wandering and in a secluded area, they see a bunch of people with mismatched eyes, just like the cats. At first, they're just standing there, absolutely still, then they notice the protagonist & co and make a series of strange noises before charging at them. The protagonist and friends run away from these guys, who are acting exactly like the zombies of a Zombie Apocalypse
As they make it back home, they realize there are zombies everywhere. They finally get into the apartment building, looking for weapons, and the lights are out. In the dark, they see a pair of mismatched eyes and panic, then realize that those are cats' eyes. They realize that the cats may have been differentially affected by whatever it is that caused the zombies. Then the protagonist remembers her two dead cats, and suggests the theory that zombies are reanimated dead, and cats come back more than humans do.
Based on this, they decide that cats are the key to solving this zombie apocalypse, and take some mismatched-eye cats and go looking for a lab of some sort to study them. But now I'm stuck. What kind of solution might they find? Why would the cats come back better than the humans do?
If I'm asking for advice on a story idea, don't tell me it can't be done.