Voldemort had been laying somewhat low for a couple months. Refining his new plans since he was no longer focused on killing Harry. Then one day Hermione and Bellatrix had come to him with a plan to ensure Harry's continued survival. He looked into Harry's mind who he could tell was feeling particularly happy at the moment. Harry was planning a trip to muggle London with Ginny, Ron and Lavender Brown. When Voldemort told Bellatrix and Hermione of the plan she guessed where they would apparate into close to the restaurant and they set out to spring a trap.