Sil's head turned straight ahead and she plucked something from the back of her head, placing the pea-sided device in a slot on Cassie's prosthetic. The arm twitched, whirred and then folded in on itself. The hand collapsed into the wrist, the forearm retracted and bent at the elbow to join with the upper arm and the whole thing swung via her shoulder until it was behind her. At the same moment Sil grabbed Cassie's left arm and attached a restraint to the wrist. It jerked her hand behind her, as if it was being pulled towards the bed by a magnet.