As hoped Mrs. Kane adjusted her weight to track his motions, then a shoe brushing the floor always to the right. The good doctor ramrod military straight hadn’t moved a muscle. Holmes raised his cane causing Mrs. Brown to change her target; behind him he heard no readjustment.
In a swift single move Holmes dropped rolled and smashed the cane to the floor producing an echoing crack. This noise was follow with a louder crack and then a final crack.
As hoped Watson realized Holmes had placed himself exactly between the women. Neither woman knew the gun trained on them.