Stumbling backwards, Harry raised his wand.

'Expecto patronum!'

A silvery wisp of vapour shot from the tip of the wand and the Dementor slowed, but the spell hadn't worked properly; tripping over his own feet, Harry retreated further as the Dementor bore down upon him, panic fogging his brain--concentrate--

A pair of grey, slimy, scabbed hands slid from inside the Dementor's robes, reaching for him. A rushing noise filled Harry's ears.

'Expecto patronum!'

His voice sounded dim and distant. . . . Another wisp of silver smoke, feebler than the last, drifted from the wand--he couldn't do it any more, he couldn't work the spell.

Chapter 1