I love what a badass Henry is for doing this.  He comes to Sherlock in the middle of having a nervous breakdown, terrified out of his wits and shaken to the core, trapped between the two possibilities of having hallucinations or being stalked by a dog-monster, and when Sherlock’s like, “I propose we wave you under this thing’s nose and see if anything happens!” Henry’s like, “…Yeah, okay.”

AND when Sherlock practically jumps in his lap to shotgun smoke off him, all Henry does is shoot John a confused look.

I think he and John might be soulmates.