Patching is a cruel punishment often meted out by the Boolooroo of the Blues on Sky Island. Patching is done in the Boolooroo's royal palace, in the Room of the Great Knife. The room is high and big, with rows of benches for spectators and a raised platform for the royal family. The great knife is like a guillotine, built into a huge framework like a derrick that reaches to the ceiling. The immense blade is so heavy that it takes the strength of seven Blueskins to raise it, and the Boolooroo himself pulls the cord that releases the blade. Set below the blade is another framework set on rollers to which prisoners are tied to keep them from wriggling and to make sure the slicing is accurate.