Ernie wasn't really able to sleep despite being absolutely exhausted, and heard the knock on the door. It took a bit more effort than usual for him to hall himself off of the couch and to the door, which was something unusual for him when he was expecting company.
He hadn't slept at all the night before firstly from the whole incident with Hann and Justin then the emergency staff meeting. It certainly did show, despite the alerting potions that he had used throughout the day. They didn't take away the tiredness, they just kept him awake enough to tolerate the day. "Hi Jasper," he said, as he opened the door to let his friend into his flat. "How are you faring? I'll go get some tea," he said, as he headed towards the kitchen.