Description
It was because the good-natured Bobbsey Twins were seeking a certain type of garnet for their friends, the Cottrells, that the children decided to have a picnic out of Mine Hill. There they met Pickax Pete, an old miner who lived near his abandoned mine on the hill. Pete knew all about the dark red garnet stones though he had long since stopped operating his mine.
But when Pickax Pete told the Bobbsey Twins that someone or something was moving down in the mine, of course Nan and Bert, and Freddie and Flossie simply had to climb down the ladder and explore the dark, echoing passageways.
What they discovered in the mystery cave beyond the mine and whom they found there make an exciting and amusing adventure-mystery that will thrill all younger boys and girls.