An old legend provides the clues for this delightful treasure hunt in the Yorkshire dales. The seekers are Nan and Mary from the farm, Peter from the inn, and Adam Forrest, the head boy from Nan's school. The first clue is concealed in the old sideboard at the inn and the last somewhere inside a hill; but the one that seems most important is a unicorn. Adam is too old to bother with unicorns and thinks he can uncover the mystery using science. Mary is too young to be concerned with science and calls on the fairies for help, and prepares a grass rope so that she can catch the unicorn properly. Whether the treasure is at last discovered by science or by magic is told in this absorbing book by William Mayne.

First published in 1957, "A Grass Rope" was awarded the Carnegie Medal for that year.