Orphaned boy detective Narutaki finds himself up against a tour-de-force of thieves, tyrants, and an archenemy who may yet prove more than his match! With the city overrun with crooks and villains of all breeds and creeds, Narutaki must protect Steam City at any cost from those who would destroy it with their nefarious desires.

Narutaki, Ling Ling and Goriki have their hands full with four new cases of murder and mayhem that baffle the local police. When Steam City's legendary protector, the White Dragon, starts "liberating" jewelry stores of their wares, Narutaki suspects a criminal element...

The villains of Steam City are back at it again! First, Crimson Scorpion has an ingenious plan to steal a pair of priceless black diamonds by seducing Detective Onigawara. Then, Ling Ling's crafty sister Lang Lang is determined to be "an angel in black" for a sick little girl, fulfilling her last wishes... even if it kills her!

Steam City is under attack! A chance run-in with Dr. Guilty turns Ling Ling into a hostage. Narutaki springs into action, but when the doctor reveals the damage he intends to unleash, it becomes clear that much more than a friend is in danger. Yet Dr. Guilty isn't the only one with Steam City in his sights. Knight Phantom emerges from the shadows and promises to destroy the entire town - unless Narutaki agrees to own up to a dark secret from the past.

In a past that never was, in the Age of Steam, masked dandies, dastardly supervillains, and sentient machines stalk the streets of Steam City by night. Are the wits and reflexes of wunderkind detective Narutaki, pretty nurse Ling Ling, and their robot Goriki enough to thwart evil in this strange world?

Narutaki's only allies are Kawakubo, his butler; Ling Ling, a beautiful nurse; and Goriki, Ling Ling's steam-powered robot. And when Narutaki finds himself putted against nefarious villain Phantom Knight, cunning thief Red Scorpion, and brilliant-but-insane scientist Dr. Guilty, Narutaki will need all the help he can get!

Mystery and murder! Mr. King is Steam City's bestselling horror author, but when one of his creations, the Emperor of Steam, comes to life and begins killing people, he's Suspect Number One! Only his fan Ling Ling believes in his innocence and to prove it, she leaves Narutaki to become King's nurse and housekeeper!

Up and coming defense lawyer Liza Fleisher is in danger when she successfully defends a corrupt Steam City business man and becomes the target of a vigilante serial murderer, Don Death! Now, as Liza's bodyguard, Narutaki must uncover the secret to Don Death's identity before he can strike the fatal blow... and the woman he's guarding may have the answer.

Steam City is under attack by the wily Dr. Guilty! To stop this madman from wreaking any more havoc, Narutaki and Goriki must combine their strength against the (not so) good doctor and his new Megamaton: Shadow Bolt No. 3!

In a past that never was, dastardly supervillains and sentient machines stalk the dark streets of Steam City. Red Scorpion is back, and this time she's after the precious Celestial Globe. Can Ling Ling and Goriki stop this master criminal and her gang of sleazy thugs?

Everyone assumes that Le Bread is the boy criminal who kidnapped the seven beautiful "Angels of Music" and destroyed their vocal chords, but Narutaki knows that even if Le Bread is guilty, the terrorizing and brutalizing comes from another source: the evil Phantom Knight.