Cassandra Clare is known for her series: The Mortal Instruments, but many don’t know about the series she wrote after that is supposed to be a prequel series to the Mortal Instruments: The Infernal Devices.

Clockwork Angel– The year is 1878. Tessa Gray descends into London’s dark supernatural underworld in search of her missing brother. She soon discovers that her only allies are the demon-slaying Shadowhunters—including Will and Jem, the mysterious boys she is attracted to. Soon they find themselves up against the Pandemonium Club, a secret organization of vampires, demons, warlocks, and humans. Equipped with a magical army of unstoppable clockwork creatures, the Club is out to rule the British Empire, and only Tessa and her allies can stop them…

Clockwork Prince–In the magical underworld of Victorian London, Tessa Gray has at last found safety with the Shadowhunters. But that safety proves fleeting when rogue forces in the Clave plot to see her protector, Charlotte, replaced as head of the Institute. If Charlotte loses her position, Tessa will be out on the street—and easy prey for the mysterious Magister, who wants to use Tessa’s powers for his own dark ends. With the help of the handsome, self-destructive Will and the fiercely devoted Jem, Tessa discovers that the Magister’s war on the Shadowhunters is deeply personal. He blames them for a long-ago tragedy that shattered his life. To unravel the secrets of the past, the trio journeys from mist-shrouded Yorkshire to a manor house that holds untold horrors, from the slums of London to an enchanted ballroom where Tessa discovers that the truth of her parentage is more sinister than she had imagined. When they encounter a clockwork demon bearing a warning for Will, they realize that the Magister himself knows their every move—and that one of their own has betrayed them. Tessa finds her heart drawn more and more to Jem, but her longing for Will, despite his dark moods, continues to unsettle her. But something is changing in Will—the wall he has built around himself is crumbling. Could finding the Magister free Will from his secrets and give Tessa the answers about who she is and what she was born to do?

Clockwork Princess– THE INFERNAL DEVICES WILL NEVER STOP COMING! A net of shadows begins to tighten around the Shadowhunters of the London Institute. Mortmain plans to use his Infernal Devices, an army of pitiless automatons, to destroy the Shadowhunters. He needs only one last item to complete his plan: he needs Tessa Gray. Charlotte Branwell, head of the London Institute, is desperate to find Mortmain before he strikes. But when Mortmain abducts Tessa, the boys who lay equal claim to her heart, Jem and Will, will do anything to save her. For though Tessa and Jem are now engaged, Will is as much in love with her as ever. As those who love Tessa rally to rescue her from Mortmain’s clutches, Tessa realizes that the only person who can save her is herself. But can a single girl, even one who can command the power of angels, face down an entire army?

“You can’t be serious —” Tessa began, but broke off as the door to the library opened, and Charlotte entered the room. She wasn’t alone. There were at least a dozen men following her, and — Tessa saw, as they filed into the room — two women.

Tessa gazed at them in fascination. So these were Shadowhunters — more Shadowhunters in one place than she’d ever seen before. She stared at the two women, remembering what Will had said about Boadicea, that women could be warriors as well. The taller of the women had powder-white hair wound in into a crown at the back of her head; she looked as if she were well into her sixties, and her presence was regal. The other of the women was younger, with dark hair and catlike eyes. The men were a mixed group, all in carefully tailored dark clothes: the eldest of them was an elegant-looking gentleman with an iron-gray beard and a steely gaze to match; the youngest was a boy probably no more than a year older than Jem or Will. He was handsome in a pretty sort of way, with delicate features, tousled brown hair and a watchful expression.

Jem made a noise of surprise and displeasure. “Gabriel Lightwood,” he muttered to Will, under his breath. “What’s he doing here?”

Will hadn’t moved. He was staring at the brown-haired boy with his eyebrows raised, a faint smile playing about his lips.

“Just don’t get into a fight with him, Will,” Jem added hastily. “Not here. That’s all I ask.”

“Rather a lot to ask, don’t you think?” Will said, without looking at Jem. He was watching Charlotte as she ushered everyone toward the large square table at the front of the room; she seemed to be urging everyone to settle themselves into seats around it. “Mr. Wayland,” she was saying, “and Mr. Harrowgate, here, by the head of the table, if you please. Aunt Callida — if you’d just sit over there by the map —”

“And where is George?” asked the gray-haired man, with an air of brusque politeness. “Your husband? As head of the Institute, he really ought to be here.”

Charlotte hesitated for only a fraction of a second before plastering a smile onto her face. “He’s on his way, Mr. Lightwood,” she said, and Tessa realized two things — one, that the gray-haired man was most likely the father of Gabriel Lightwood, and two, that Charlotte was lying.”