What Novels Use Linear System Substitution In Their Mystery Plots?

Elena Cordova designed revolutionary algorithms for a multi-million-dollar company. The only formula she couldn't solve? Her own marriage. After seven years of being the invisible wife to a cold billionaire, Elena is finally trading in her wedding ring for her worth. Marcus Ashford married her for obligation, hid her from the world, and replaced her with a woman who played the perfect stepmother. But when he finally pushes her too far, he discovers that the brilliant, betrayed woman he dismissed has been running calculations all along. Now, Elena is back in the boardroom, her mind sharp, her fortune growing, and a handsome rival billionaire watching her every move. She wants revenge. She wants vindication. She wants her daughter back. Marcus thought she was a social climber. He thought she was docile. He thought he could replace her. He was wrong. He used her for her brilliance. Now, she'll use her brilliance to take everything back. Divorce is just the beginning of her beautiful, calculated comeback.

On her unconscious bed, her husband gave the order to abort her child. Their child. Driven by lust and desperation for power, Killian Powell framed Rose Webster just to divorce her and marry her twin. At what price? To easily buy his way into her family's corporation. Rose had the evidence to expose her husband's true face to the world and tear him down. But of what use was it when her vicious parents threatened to stop the treatment of her sick daughter if she dared release the evidence? Like always, they cared more about what they stood to gain from a traitor who stabbed their daughter—a man they once despised when he was nothing. As much as Rose couldn't trade the life of her daughter, she couldn't bear the internet stigma and mockery. Not to mention her job as a detective was suspended as if she were some criminal. The whole world seemed to close in on Rose until redemption came in the form of a dangerous offer. When solving a risky murder case was the only way to get back at her ex-husband and also keep her child safe, how far would she go to ruin her ex?

With her enemies in pre-civil war Virginia still seeking her death, Esmerelda is forced to return to the future only days after wedding Lance. Because it was necessary to fake her death in order to stop her enemies from following her to the future, her new husband, Lance, was forced to stay behind. He’d placed a magic box for them to communicate until he found a way to safely be with her beneath the floorboards of the house. Now, she must find it. A task that is easier said than done! “The Magic Box” is book two of the exciting paranormal-romance-mystery-thriller Esmerelda Sleuth Series

From New York to Rome, Istanbul, Cairo, Iceland, and beyond, Adrian races against an invisible enemy that has protected the truth for over five hundred years. But as the final cipher draws closer, he realizes the greatest danger isn't unlocking the secret... it's surviving it.

A series of past murders catch the attention of the police and the media. All the people who were killed were women, all of which had some sort of relationship with a well known and successful businessman named Asriel Parker. For some reason, the murders all point to him as the number one suspect and connection between them. The reasonable thing to do is to put him behind bars but there is one problem. "Everyone is innocent in the eyes of the law until proven guilty." There isn't a shred of evidence that actually pinpoints Asriel Parker as the culprit. With that statement in mind, Selena March, a good police officer and detective is sent undercover as his live-in Personal Assistant to dig up whatever information she can use to put the murderer behind bars. Selena has no idea what she signs up for but she knows for a fact that falling in love is not part of the whole 'undercover' mission

Meet Esmerelda Sleuth. Sleuth is her name and investigating is her game. (Paranormal Investigating, that is.) Esmerelda makes a good living as an investigator in a rather progressive firm. She lives a stable and sensible life until she meets Lance; an old money "hottie" who works for a real estate firm next to her building. After accepting an invitation for a weekend getaway party, she quickly discovers that Lance has a secret. He is wealthy. That part is true. And, yes, he's procured a job as a realtor in the building next door. His secret is that he belongs to an underground society of humans who didn't abandon their connection to magic centuries ago when religion declared it evil and he has traveled through time specifically to find her and bring her back to his time to marry him. If that isn't enough of a far fetched tale to absorb, he informs her that she was born in his time to a family belonging to that same secret society and was promised in marriage to him as an infant. When enemies who didn't want to see the union of families take place made attempts on her life, her parents sent her into the future and erased her memories of them as a precaution. Possessing virtually no belief in magic, ghosts, psychics, time travel, etc., it takes some doing on Lance's part to convince her to believe his story and go back with him. When she does, the lies, deceit and attempts on her life start all over again. Will she escape emotionally and physically unscathed? "The Other Side Of the Mirror" is a steamy-paranormal-romance- mystery-thriller and book one of the Esmerelda Sleuth series.