A gapper is a bit like a 'burr' but it is a dangerous thing. When it attaches itself to goats the goats become very unhappy and even stop giving milk. There is nothing gappers like more than goats and nothing goats hate more than gappers. When gappers get your goats it means trouble. In one small town gappers are a real pest and it takes the ingenious approach of Capable to find a solution - ife a solution exists at all.