They work with detachment, eerie. A melted gauntlet is cut away, as is the shrivelled hand inside. Charred veins like overcooked spaghetti are stripped from the forearm and the limb is re-plumbed. When a match for the original hand is found, animate stitches assist surgical lasers to get the job done. Bones and skin and sinew connect. At the last moment they extract the essence spark from the new hand, leaving the whole shell empty, ready for repossession.
