Dumbledore advises Hermione and Harry to use Hermione's time-turner, a device she has been using to double-up on classes, which permits them to go back in time and save Buckbeak, who carries Black away to safety.
Dumbledore advises Hermione and Harry to use Hermione's time-turner-up on classes and save Buckbeak. Turner is a device. She has been using to double a device. Buckbeak carries Black away to safety. Classes permits them to go back in time.