Okay so here is what's going on: The ministry sent Ron to make the swap between Death Eaters (there were two) and the girls. Harry and Neville took polyjuice and went with them. They have doses stashed on them in expanded pockets. The girls are home safe and last night Harry and Neville waited until after dark to spring an attack on the Death Eaters (there were three of them). Neville was injured and is in St. Mungo's this morning but they managed to arrest all three of them.