Which James Rollins Book Starts The Sigma Force Series Story Arc?

The woman standing there was nobody that Scars had ever laid eyes on before, but holy God, he knew her. He knew her on a cellular level. In his blood. In his bones. In his heart and in his cock. He’d dreamed about her and he’d waited for her. He’d been looking for her forever, and now here she was. ** Six years ago, Zoe Parish fled Denver after a brutal encounter with a motorcycle club man, swearing never to trust one again. Now a mother and desperate to help her oldest friend, she returns when Wolf Connor promises his club is out of the life and she’ll be safe. Back in Denver, Zoe keeps her guard up, especially around Scars, whose effect on her is far more unsettling than she wants to admit. Vic “Scars” Innis has spent twenty-two years loyal to the Road Devils, earning his place as Vice-President. He thought he was content, until he meets Zoe. From the first look, he knows she’s the missing piece, even if she despises everything he represents. As danger closes in and an enemy threatens to destroy their fragile peace – and take Zoe’s child – Scars and Zoe are forced to confront their pasts and each other. The question is whether their bond will make them stronger… or finally tear them apart for good.

Elias has lived his whole life as a lie. Born a male Omega in a world where his kind are owned, traded, or bred, his only chance at freedom was to disappear behind a forged identity. Now he’s “Eli Arden,” Rank 2 at the most ruthless Alpha academy in the nation. No one suspects the truth; Not the instructors. Not the students. Not even the wolves who want to beat him. Only one person watches too closely. Ronan Vesper: Rank 1, cold-blooded, terrifying, heir to an Alpha dynasty—and the one Alpha Elias can’t afford to provoke… or attract. But suppressants are failing. Instincts are waking. And when Ronan catches Elias mid-dose, something shifts between hunter and prey. He should have exposed him. He didn’t. Now Ronan is circling him like a secret he wants to own. And Elias is running out of time to keep his body and identity under control. In a school where the weak are erased and the powerful take what they want… What happens when the deadliest Alpha discovers his greatest rival is an Omega?

"Max DiSalvo gave his entire life to the SEALs. He would have married—he certainly enjoyed women—but he never could find one who understood his dedication to the Teams. It takes a certain caliber of woman to be a SEAL wife. Now, at 48, he is out of the SEALs, running his own commercial fishing company in Maine where he grew up, and waiting for his assignments from DHS.Regan Shaw, a SEAL widow, is an Intelligence Operations Specialist with DHS. Part of her job is analyzing information to assess threats, and she’s discovered a doozy—there is a secret group of very wealthy people who are smuggling terrorists into the country. And word has come down that a high-level member of the government is clearing the way for them.The group is about to have one of its executive meetings at an exclusive resort in Texas, and that’s where DHS is sending the two of them.SEAL Undercover is created by Desiree Holt, an EGlobal Creative Publishing signed author."

Jagger has a double life, a life bound to the law and another where he breaks every law known to man as he does his job as The Enforcer for the New York City Mafia. Jagger has been engulfed in sorrow since he lost the woman he loved and their baby when she got caught up in the dark side of his life.  Jagger sank into depression, drugs, and alcohol while trying to fight off his demons and get revenge for what happened to the woman he loved and their baby. The man that killed them is a ghost, a ghost Jagger can’t seem to find. Jagger rebuilt his life, becoming the most reputable criminal lawyer in New York City, and now he needs to face the man he stole his woman from in court. His past seems to come back to haunt him when he meets the only woman who has made him forget about his past and wants to be with someone again.  Calliope Flores is a law student who is suing one of her professors for sexual harassment. Her life has turned upside down, as she has to deal with what happened and relive it every second of every day. When she meets the lawyer representing her professor, her disgust for him mixes with lust, desire, and a mind-blowing sexual attraction.  Callie tries to fight off her desire while cultivating the anger that fuels her body. Getting mixed up with a big-time lawyer from the opposite side seems like a mistake Callie is willing to make if it will make her feel alive again.  This is the third and last book of The Legacies series. This book can be read as a stand-alone, but it is recommended to read the other books first for better comprehension. 

Keeping her safe has become his life's mission. 
 Gage Hendrix is a man without roots. As an MSD Team Leader for the Department of State, he operates in high-threat environments. Serving in dangerous postings around the world, his team provides emergency security support and crisis response. Keeping the US ambassador's daughter safe in Sri Lanka? An unusual assignment for an "action group" used to dealing with evacuations, wars, incursions, and coups. Expecting a spoilt princess, Gage finds a hard-working therapist with a huge heart and sad eyes. 
 Hiding from heartache is no longer an option. 
 Chantal Durant's best friend has gone into hiding with intel that could lead to a nation's upheaval. Enemies have targeted the last person who helped her to escape… Turning a tragic past into a constructive existence, Chantal dedicates herself to helping others. She likes her work, likes her routine, and doesn't like that her safety is now in the hands of a cocky MSD agent. Her undeniable sexual attraction for the ruggedly handsome bodyguard would not only end his career but could get them both killed. 
 As multiple threats close in, Gage is faced with harrowing decisions. Trapped in an unfamiliar landscape, both Gage and Chantal will have to act fast to make it out alive. "If you're looking for the perfect blend of action and steam set against the backdrop of exciting international locales...your first stop should be Louise Dawn." - Janie Crouch.

The mission was simple: Protect her. The reality was dangerous: He loved her. ​Evander Sinclair is a man of steel and silence, an elite operative who never breaks protocol. But when he is assigned to guard Elena Montgomery, the lines of his duty begin to blur. She is a princess in a gilded cage, and he is the only one who sees her true soul. ​To give her the freedom she craves, Evander does the unthinkable—he takes her off the grid. But in the shadows of their brief disappearance, secrets from their past begin to surface. Between a ruthless ex-husband and a hidden truth that could shatter their worlds, Evander must decide: ​Is he her protector, or her downfall?