The answer to that is yes, but it's not that simple, so she doesn't answer directly. "Sherlock didn't know that at the time. He was investigating a hitman that went by M. M had a very distinct calling card. Most of the bodies of M's victims never turned up. What was left behind at the crime scenes was blood. All of the victim's blood, in a pool on the floor."

She pauses for a moment, letting that sink in.

"One day," she continues, "Sherlock went to visit Irene. And found a pool of her blood."