Sherlock Holmes and the Mystery of the Forgotten Password

In The New Adventures of Old Sherlock, a brand-new series, Sherlock Holmes is feeling like an analogue detective in a digital world!The world's richest and most obnoxious Tech Bro (freshly decamped to the English countryside) has invited Sherlock Holmes to visit . and vanished before Holmes gets there! Did he intend for the Great Detective to investigate his disappearance?Dr Watson is alarmed that Sherlock Holmes is growing forgetful.
He can hardly remember why he came into a room, and keeps misplacing things. Is he finally losing his memory? Or is all a ruse, to engage a villain who may or may not be a piece of malevolent AI? And while we're talking about things being de-crypted, could Holmes's supposedly deceased adversary Moriarty be behind it all? Only Sherlock Holmes can save the day - and of course Watson, if he can recall where he wrote down his damned list of passwords*!*They've got to be somewhere.