How does Doyle add deceiving in the script?

There is a great deal of deciet and deception in this work, starting with Porlock and Moriarty. The central deception, of course, is John Douglas, who is actually McMurdo, who is actually Birdy Edwards. Edwards deceives all of the Scowrers as well as Ettie initially; then in England he deceives Cecil and his wife. The deception deepens with his faked death, but even then it is not enough to fool Moriarty (or Holmes, of course). Deception is used for both moral and immoral reasons. Moriarty deceives to gain power; Edwards deceives in order to gain access to a society of murderers whom he seeks to bring down. Doyle suggests that deception may be useful but that one has to be very careful to not lose himself within the disguise.