Ms. Ra was a vampire
When Tae-Ju was puréeing that apple, she cut herself, and a drop of her infected blood made it into Mr. Ra's apple purée, then she drank it. Was anyone else a bit disappointed that Ms. Ra being a vampire didn't come up later in the movie, especially when they were dying in the sun?
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If the rule you followed brought you to this, of what use was the rule?