Harry sneered and went over to Cho, cutting away at the rope around her ankles. When she was free, Harry swam over and was about to cut Hermione free as well, but then hands grabbed him and pulled him back. In response, Harry whirled around and punched the closest merman right between the eyes, and he floated away with a dazed expression. The other merpeople looked at Harry in bewilderment for a moment, then collectively hissed and pointed their spears at him.