Dr Watson might have surmised that both Professor Moriarty and Sherlock Holmes met their deaths in Reichenbach Falls.
Three years later Holmes returns from the dead, Watson faints at the shock of seeing him. Holmes recounts the encounter he had with Moriarty, why he had to still lie low and the reason for his return.
Moriarty's men are still keeping watch in case Holmes does return. The death of The Honourable Ronald Adair is the reason he has come back.
Holmes believes the old shikaari, Colonel Sebastian Moran one of Moriarty's important associates is responsible for Adair's death and also aims to kill Holmes if he is out in the open.
Adair believed the Moran cheated in a game of cards. Holmes sets up a trap for the old shikaari, just like the ones Moran set up in India when he shot his tigers.
It is great to see the return of Holmes and the flashback to the previous episode. The central mystery is unfortunately thin. Brett gets to be in disguise which fools Watson.
The Return of Sherlock Holmes would see the characters of Holmes and Watson as older. Edward Hardwicke took over from David Burke who left the role to concentrate on theatre and spend more time with his young son.
Personally I preferred Burke's take on the role, he had a bit of swagger and some mischief.
Interestingly I found out from an interview by the producer June Wyndham-Davies that Edward Hardwicke spent time as a young man in Hollywood where his father Sir Cedrick Hardwicke was based. Edward met Nigel Bruce who would often pop round to their house. As a tribute Edward was determined to have a bit of Nigel Bruce in his performance as Dr Watson.