He sighs quietly and takes back the vial, watching the tension -- a preparation to fight or flee -- spread and then cut off quite suddenly when Marvolo downs half the vial himself. "If it’s an abortifacient I’m at even more risk of it damaging me than you are given I do not even have the right anatomy for it. But it is not one. It’s a Truthful Mind potion; all it will do is make it impossible to directly lie to me for the next hour or so."