Graveyard scene

[Kathryn Cawte]

No: HPFGUIDX 54399

 A friend of mine and I were just discussing the fact that whenever Harry
has to face Voldemort he always has to do it alone (does anyone think that's
significant btw?) when she pointed something out I hadn't noticed. In the
graveyard scene in GoF harry and Cedric arrive in the graveyard, they see
someone we soon discover is Peter carrying a bundle, which turns out to be
Voldemort, Harry hears a high pitched voice (Voldemort) say 'kill the spare'
and then another voice (presumably Peter) say 'Avada Kedavra'. So someone
other than Voldemort cast the spell and yet Cedric's ghost emerges from
*Voldemort's* wand later due to the priori incantum effect. So why is Peter
casting the spell with Voldemort's wand?
I don't remember whether they said if his wand was found along with his
remains after his presumed death but I would assume somewhere in Knockturn
Alley or somewhere similar there is somewhere he could get a wand on the
black market and I doubt he'd have wanted to go a whole year without one -
so why is he using Voldemort's wand? We already know that using another
wizard's wand isn't as effective as using your own.

K