Oh wow, this is great! I thought when I read the pairing that it would be good (somehow, it looked like a pairing that would appeal to a good writer), and indeed, I was hooked immediately. Their voices are so well-done, and I love that we get a feeling of what it was like for Dudley and his friends that he was taken out of his world so suddenly – and then dropped back in without so much as a warning. I also loved the glimpse of his attitude towards his parents, and his relating to Harry over the desire to get away from them ("and I said to Harry: just magic me out of here PDQ before I'm forced to throttle the both of them"). Piers, too, is a great character. In short, a true essence-of-Beholder fic.
Just two of many great lines as examples for what I love about voice and characterisation:
"Der." Piers wasn't quite eighteen yet, so he'd be detained at Her Majesty's pleasure for murder. Her Majesty would surely understand the extenuating circumstances wherein Piers' best friend was a braindead, insensitive prick who deserved the shallow woodland grave Piers would give him.
His mum would probably say it was Fear of Intimacy or some such rubbish she'd read about in Women's Weekly but it seemed to Piers that he and Dudley had always had intimacy coming out their ears.
Affecting, touching, and strangely romantic. I'll kick seven shades of shit out of anyone who says otherwise.