'I do not believe that a man can be truly happy unless he fully understands what he is and can act accordingly ... how can it be wrong to be happy?'

These lines are taken from Will's diary, a seemingly innocuous exercise book which details his house-breaking activities. Will carefully selects houses - forty-seven so far - ensuring their owners will be in. As they cook their supper or watch television, Will (wearing surgical gloves and leaving no trace behind) enters not only their houses, but their secret lives. A secret museum, housed in his loft, is 'held together by sex'. All his trophies are carefully catalogued and he keeps a very precise diary of his activities and his thoughts.

All his life Tom Kendall had lived as quietly and normally as possible ... but he gave people the creeps ... 'kids didn't like him, or the cat'. When Tom discovers Will's diary he decides to adopt the same quest for happiness. Tom has problems of his own - a difficult temper, problems with his girlfriend, Maddie, and an overwhelming sense of powerlessness. Perhaps Will's diary holds the key?