The Baker Street Irregulars were among Sherlock Holmes's large deck of trump cards.
They were made up of a group of street children employed by Sherlock to run errands and track down information. Due to their age and social status, people paid no attention to them, and they were practically invisible within the city's confines. Even if they were to trail someone undisguised, it rarely raised any suspicions.
"Instead of letting them wander around aimlessly around the streets, it's better to give them something to do. Don't underestimate those urchins—sometimes they are even better than a dozen police officers. They can go everywhere and hear everything," said Holmes as he picked up his violin.
"Since we have nothing else to do, any songs that may tickle your fancy?"
"Please, just play whatever you wish."
"Then it'll be Sarasate's Introduction and Tarantella," said Holmes. He placed the violin between his chin and left collarbone and began playing.
