This puzzle asks you to find the single category linking five clues: Crust, Mantle, Core (mostly iron and nickel), Tectonic plates, and Magnetic poles (North+South). The answer is Parts of the Earth. The clues look unrelated on the surface but share one precise category. Read all five before guessing — the link should feel natural on every row. With only "Crust", many categories could fit. Hold your first guess and watch what clue 2 eliminates. "Crust" and "Mantle" must share one repeatable link — not a coincidence between two words. By clue 3 ("Core (mostly iron and nickel)"), "Parts of the Earth" should explain all three without bending meanings. "Tectonic plates" strengthens "Parts of the Earth" rather than opening a new theory. The final clue ("Magnetic poles (North+South)") confirms "Parts of the Earth" — if it still fits naturally, the category is locked. Use the Solution tab above for an interactive clue-by-clue walkthrough, or the Solved board tab for the complete answer at a glance.