Mycroft hires Holmes and Watson to retrieve compromising photos of a minor royal held on the camera phone of Irene Adler, a ruthless and brilliant dominatrix who also trades in classified information extracted from her rich and powerful clients. Holmes obtains Adler’s phone, but discovers it is booby-trapped and requires a code to disarm it. When Adler discovers that the CIA are on her trail, she disappears and is then apparently killed, only to reappear months later when the coast is clear. Adler manipulates Holmes into deciphering a coded message on her phone which she obtained from another well-connected client. She sends the message to Moriarty, who in turn uses it to foil a British counter-terror operation. Adler then goes underground again. The episode concludes as Mycroft tells Watson that she has been killed by a terrorist group in Pakistan. This is another decoy: Sherlock helped her escape when she was on the brink of death.

Artwork: London Eye by telegram (Stock.xchng)