The arrival of the Dementors in Little Whinging seemed to have breached the great, invisible wall that divided the relentlessly non-magical world of Privet Drive and the world beyond.
Harry had seen them at it during his evening walks around Little Whinging; he had spent most of the holidays wandering the streets, scavenging newspapers from bins along the way.
And his reward was to be stuck in Little Whinging for four solid weeks, completely cut off from the magical world, reduced to squatting among dying begonias so that he could hear about water-skiing budgerigars!
It was impossible . . . they couldn't be here . . . not in Little Whinging . . . he strained his ears . . . he would hear them before he saw them . . .