Warehouse Key

The Warehouse Key is an item that appears in Paper Mario. It opens a warehouse in the eastern part of Shiver City.

When Mario must reveal who murdered Mayor Penguin, he'll come across a locked door. He'll also stumble across a key trapped underneath Shiver City's frozen pond. To break the ice, Mario must Tornado Jump on the lake the times, or blow it up with Bombette. Once the ice is shattered, Mario can dive down the key with Sushie to claim it.

Trivia

 * Mario can't get the key before visting Mayor Penguin. If he starts to break the ice at that point, he'll be stopped by the Penguin Patrol.