There was an issue with Snape’s quality control and he went to the lab to sort it out. The building was in a perfectly respectable section of the warehouse district and pretended to be a laboratory for sensory science, primarily food flavoring testing. In fact, Theo walked through the entire legitimate side of the laboratories, smiling at all the earnest graduate students in their lab coats. He was in his all black suit today because it hid blood better than any of his other color schemes.