The great troll war

"Sixteen-year-old Jennifer Strange and her sidekick and fellow Orphan Tiger Prawns have been driven to the tip of the UnUnited Kingdoms--Cornwall--by the invasion of the Trolls. Their one defence is a six-foot-wide trench full of buttons, something which the Trolls find unaccountably terrifying (it's their clickiness). Worse than being eaten by Trolls is the prospect of the Mighty Shandar requisitioning the Quarkbeast and using him to achieve sup...