The corners of Newt's mouth turn downwards into a frown at the mention of what'd happened. Yes, he's aware; yes, he feels guilty as hell about it, even though everything to do with Kieren is still a work in progress. It's not like he's ever worked on the undead before, it's just a bit of a shift from working on kaiju biology for the better part of his adult life. So he's doing his best, he and Kieren both are, but that particular side effect had not been ideal, to say the least.

All of what Sirius is saying sounds, well, pretty fucking serious, and Newt's frown only deepens as the list of symptoms grows longer. He does't want to freak the guy out by saying they ought to do something pronto, but he doesn't want to make it seem like he's brushing anything off, either. It's a fine line, but he takes a breath, nodding slowly as he tries to work through his thoughts.

"Okay, well. That's not great, I'm not gonna lie, but we expected there might be some hitches. Whatever they did in his world to produce that medication he used to take isn't something I've been able to fully replicate yet." Biting down on his lip, he glances behind him at the lab before looking back at Sirius. "I've got some of his samples up there. I'll probably need new ones to compare, see if anything's different, but I could show you what I'm working on. If you want."