Severus took the letter when offered, brow furrowed as he glanced over it. He had to admit it, albeit grudgingly, that the boy had a valid, logical point. If Nagini were here, it was quite probable that destroying the Dark Lord via the horcruxes would not be possible. Which meant that the first order of business was going to be to determine if, in fact, the snake was present in Los Angeles.
Needless to say it wasn't something Severus was particularly looking forward to. After all, Nagini was how he'd met his end before. He didn't fancy being in the same vicinity as the creature again.
Passing the letter to Draco, so he could read it as well, the man turned his dark gaze back to Harry. "He will want to know, of course, why your scar hasn't been giving you troubles, Mister Potter," he murmured. "Given the amount of... attention he's been putting into his call as of late, he no doubt has begun to wonder such things as well."
It was a simple statement of fact, more a warning of the ire the Dark Lord would suffer once he realized that his connection to the Boy Who Lived no longer truly existed. At this point, it was clear that he was simply gathering his followers and determining his next course of action. Learning that his greatest adversary had already defeated him in another place and time was certain to make him step-up his plans and perhaps focus more on Harry's family and friends than he'd been doing thus far.
Severus knew that Harry, too, was no idiot (although he was loath to admit such a thing) and had no doubt already deduced such a fact himself of course. He simply refused to allow the man a chance to claim he wasn't aware of a potential risk, later down the line, should it occur.
Not giving any indication as to whether that - or anything else in this place - would be motivation enough for him to once again play the part of spy, the former Head of Slytherin instead waited for Draco's own response to the turn of events thus far. He'd give his answer in due time. For now, it was time to see where his former pupil stood on the issue.