Zombieland
Madison is in the back seat eating something. She starts turning, and others assume she’s been bit. I’m looking, and thinking how weird it is, that they decided to make it look a lot like an allergic reaction. Her eye is swollen, her lips are swollen, she starts vomiting, her speech isn’t clear, she’s stumbling.
They get rid of her.
Then we see other characters turning. Some similarities, like the vomiting and stumbling, but not so much detail. I figured I was wrong about Madison.
Then....Madison shows up again, fine. And she says it was an allergic reaction.