[1][2] It is the second book in the series about the race of little people called the Minnipins, being a sequel to The Gammage Cup.

First of these is Glocken, the town bell ringer who has become obsessed with adventure after reading the account of the battle against the mushrooms; Scumble, the town fish presser and sluice gate keeper; Crustabread the loner; Gam Lutie, a village elder who is overly concerned about her family treasure; and a minnipin woman name Silky.

They also discuss an ancient relic called The Whisper of Glocken, a bell supposed to have magical powers.

A stone with a map on it that Glocken has brought with him that has been passed through his family leads Walter the Earl to believe that The Whisper is hidden in Frostbite near where the blockage is.

The Old Heroes leave them with a supply of fishcakes, medicines (including the magic salve of the Mushrooms), a book of maxims created by Muggles, and a bag of gold coins.

They dismiss his conjecture that an invisible animal dug the hole and tell him that he only got confused and went to a different place the second time.

They use a sword to cut the root, which they call a "moon melon", find out that the inside smells strongly like rotting vegetation.

Silkie lands with a thud, slowly becomes aware of a whimpering noise, and sits up to find herself and the others in a deep pit.

The whimpering is coming from a small fuzzy creature pinned under the boulder the New Heroes had pushed away from the entrance to the cave.