You know we joke, but Lestrade is probably seriously standing there, seeing REAL emotion on Sherlock’s face for what may be the first time. And he realizes that this strange little man with the cane has managed to touch something in the sociopath that no one else did. Something that the drugs may have pretended to awaken but only hurt. And for the first time, Lestrade dares to hope that the drug searches may really not be necessary anymore. Because now Sherlock’s got John.