This book spoke aloud the beginning of the riddle necessary to find the hidden time-turner:
The first is the fourth, a disappointing mark.
You’ll find it in parked but not in park.
The second is the less fair of those that walk on two legs.
Grubby, hairy, a disease of the egg.
And the third is both a mountain to climb and a route to take.
A turn in the city, a glide through a lake.