She pointed her wand at the leftmost corner of the building and muttered a spell. Then she repeated the same with the right. Familiarity with the offices meant that she knew it was a detached building sharing no common walls with any of its neighbors. The owners of the nearby shops would be pleased to have that design feature before the day was over. She was able to slip between the Daily Prophet offices and its immediate neighbor to sneak around to the back of the building. Most of the deliveries were made in the back. All in all, perhaps five minutes passed before she had the entire office building coated in an invisible containment field. If her spell managed to break out of the field, she would be universally despised and hated even more than she already was. Countless innocents would be killed as well. She couldn't afford to have that on her conscience. Only when she was one hundred percent confident that the containment field Felix Travers taught her years earlier was up correctly and impenetrable did she circle back around to the front of the building.