In this task, you're given the title of a five-sentence story and the first four sentences. Your job is to write the last sentence of the story such that it seamlessly connects with the rest of the story.

Title: Leaves. Sentence 1: Ken collected leaves and flowers on nature walks. Sentence 2: When he got home, he pressed them between the pages of his diary. Sentence 3: One day he picked a pretty, shiny dark green leaf. Sentence 4: What he didn't know was that the leaf was poison ivy!
Poor Ken had to get treatment at his local Urgent Care center!