The warning made a bit more sense now, and fright was definitely evident in Jonathan's expression as he adjusted. Up until the point Anna introduced Severus. Severus who looked familiar, and the more Jonathan looked at him and studied him, it suddenly sank in and all fear disappeared from his face as he stood, both Anna and Severus easily towering over his 5'2 form.
"Severus? As in Severus Snape?" Jonathan's eyes grew wide as he realised that it had to be. This was some kind of bizarro universe where insane things came true! Or maybe it was just a pocket dimension? Or maybe this was a vision! Like the kind of thing that Buffy actually experienced, but it was happening to him. And this woman Anna, who was maybe a witch with her teleporting, was here to tell him something important with someone as powerful as Severus Snape in tow.
Or maybe he was jumping to conclusions. Either way...
"Oh wow, that's pretty darned cool," he admitted with a smile, albeit one twinged with nerves. As cool as it was, he was still in New York City for no reason. If this was real, he'd travelled a long way in a very short amount of time and Andrew was left alone next to a really creepy, really powerful symbol of evil that was keeping the Hellmouth at bay. If this wasn't real and it was just a vision or dream... then something really intense must be happening to cause someone like him to experience this.
Which had him quickly asking in an oddly thoughtful and calm tone, belying the fact that his heart rate was slowly beginning to rise again: "Is there any way to find out if I'm dreaming or not? Because I'm not really the type to get prophetic dreams with witches and wizards in them."