Watson announces that shortly after his marriage, he "bought a connection in the Paddington district." The rest of the paragraph reveals that he's talking about a medical practice. Which is by way of distancing him from Holmes' detective work, right before Conan Doyle turns around and brings them back together.
They meet up, Holmes shows off a bit ("'I am afraid that I rather give myself away when I explain,' said he. 'Results without causes are much more impressive.'"), and he brings Watson along with him on a case.
The client of the moment is
"a smart young City man, of the class who have been labelled cockneys, but who give us our crack volunteer regiments and who turn out more fine athletes and sportsmen than any body of men in these islands"Let's pause a moment to look at the language here. First, look how the use of "but" sets up cockney as a pejorative term -- clearly Conan Doyle is not going for the "person born within earshot of Bow Bells" definition. And second, "these islands?" Ireland was solidly part of the Empire.
This time Conan Doyle has Holmes have the client tell his story to Watson -- with a caveat that feels like an authorial wink:
"I'm not very good at telling a story, Dr. Watson, but it is like this with me"
(Incidentally, Pycroft? Was it really necessary to give a client a name just one letter different from Holmes' brother? Did Conan Doyle have as much trouble remembering which letter to type?)
Anyway. Pycroft is a stockbroker's clerk who was lured away from a respectable-enough new job with promises of a much bigger salary elsewhere. But elsewhere turned out to be rather sketchy, so he asked Holmes to look into things.
(Note: I am not inclined to include racial slurs here even when they're someone else's words. But I will say that Conan Doyle throws in an utterly gratuitous one here. And the context makes it worse. Go to the story, do a Ctrl + F for "with a touch of the", and you can see for yourself.)
Suffice it to say this wasn't one of my favorites.