At hearing the young visitor's surname Watson's hand closed on his revolver and Holmes posture grew stiff with tension. "I don't know that I can help you," said at last.
"Oh, please!" cried the youth in an Irish brogue so thick it could've been cut with a knife. "You're me last hope, Mr. Holmes!"
The detective looked him up and down, made his silent deductions, and reluctantly consented. It might prove a useful lesson for both he and Watson. After all, it was monumentally implausible that EVERY Moriarty could be involved in nefarious deeds.
Now 'fess up: I cannot possibly be the only Sherlockian who is quick to judge people who are misfortunate enough to have the last name Moriarty. Or Moran.