First a Plausible A/U from the Tri-wizard on.
I would suggest, as this might go through Harry's 5th year, allow Hermione, Neville and Luna to help. Ron & Ginny would be too influenced by Molly to be that here.
Dumbles and the British ministry will HAVE to deal with the French and Voldy being back ealy. The IWC will also have to step in too.
Can't wait how this develops!
dennisud