Harry did hesitate at her voice - he always did at authority - but it was only for an instant. He was swearing when he heard her next set of words, and decided not to look out the window to check for himself. Long legs had a speed advantage - he was in the lab and out again in under a minute, three packs of blood in his hand. A favor from Butters, who - thankfully - hadn't asked what Harry needed them for.
"Oh, trust me," he said, ice layering his words. "I'll let them know in no uncertain terms."
He looked back at Sam. "You, Winchester, get to stay here. If anyone's venturing outside, it's her." He tipped his thumb towards Phaedra. "The zombies aren't interested in her. You and me are tasty flesh bags to them." He gave Phaedra an apologetic look. "No offense."