"My name is Sherlock Holmes. It is my business to know what other people don't know. What I cannot find out myself, my eyes and ears on the streets of London can find out for me."

Before Law and Order, NCIS and CSI, there was Sherlock Holmes, the most brilliant and famous crime solver of all time, and the model of modern crime detection. He was the first person to pay attention to the crime scene, frequently examining it on his knees with his magnifying glass, to find out what it could tell him about the crime and the criminal. He was the first to pay such close attention to how a person looked and acted and spoke, that within just minutes of meeting them for the first time, he knew so much about them that it seemed like magic. It wasn't. It was just that Holmes paid attention to the details of everything and everyone he saw. He was able to see and remember what no one else noticed.

But even Holmes couldn't be everywhere at once, and in many cases, he depended on a gang of homeless boys, his eyes and ears on the streets, the Baker Street Irregulars. The gang had come together slowly, one or two at a time, living on the street until they found a deserted carriage factory just off Baker Street that they called the Castle. It may have been deserted, but the boys were still careful to make sure they weren't seen as they snuck in or out through the door in the alley. In London in 1866, the homeless, especially homeless children, were sent to the workhouse, where they worked like slaves, often to their deaths, for no money, very little food, and prison-like conditions. The boys kept a close eye out for the police, not only when entering and leaving the Castle, but also when begging, one of their main sources of income, because like homelessness, begging was a crime, and the workhouse was the punishment.

However, on this fall day, they didn't have to beg, for Holmes had summoned them to do a job for him. The Amazing Zalindas, a team of tightrope artists, were dead, and Holmes believed it was not an accident. The boys were to infiltrate the circus and question the performers and workers to see who might have had a grudge against the three brothers. In short order, they discovered that the Zalindas has been spending a lot of time with a stranger that no one in the circus knew, a rope salesman. Zoloft, the knife thrower, despised the Zalindas because his beautiful assistant had run off with their younger brother. The trapeze act, the Flying Jones, wanted the Zalindas out of the way so they could take over the tightrope act, and get double pay and double prestige.

Inspector Lestrade, of the London Police, was convinced that it was an accident because the tightrope was frayed and worn at both ends, and hadn't been cut. But only moments after he began to investigate the crime scene, Holmes found undeniable proof that it was really murder. Suddenly the misshapen "M" in blood on the sawdust in the circus ring, made by the falling bodies, seemed even more ominous. Now it stood for Murder, and perhaps something else, someone else, someone who has challenged Holmes before.