Theo nodded, he'd made the same conclusion, he then listened to the rest of Dolohov's explanation and questions.
'You'll have to ask Verity about looking at him, though he has been looked at, both by something as rare as a competent healer and a very skilled curse breaker. The spell is ancient, it puts the victim in a coma that can only be woken by a very specific trigger, set by the caster him- or herself.'
Theo paused. 'The wrong trigger could in worse case scenario kill him, and none other than the correct one will allow him to wake up. As the trigger can be almost anything, I'd say that the safest bet is finding the caster and making him tell us what the trigger is - one way or another.' Montague's brother or not, if Guilian Montague had cast that spell he would be forced to give up the trigger, and Theo didn't much care for asking politely at the moment.