Antonin nodded, giving Theo a silent apology. "I'd noticed."
"The problem is, anybody could throw such a spell with training," Antonin went on. "The side of Dark Magic that destroys and rends apart is the easier side to use, after all. It might be more profitable if you could arrange for interviews with those who have had recent contact with the younger Montague, who might have noticed some change in his behavior, or other evidence of a slide into the dark. Given that he is a Montague, perhaps a lady friend or two?"