Shadow War the Complete Trilogy #981010

Two secret societies, fighting for control of a technology that could alter the fate of the world.
Two brothers, bound to protect knowledge left long ago by visitors from another galaxy.
And a woman, caught in the crossfire...

Rachel Flanagan knows she's in trouble from the first time she meets the arrogant and mysterious extreme sports instructor, who both annoys and fascinates her. She should avoid him, but when she accidentally witnesses something she shouldn’t, she has to make a choice. Believe Adam’s story about his secret society called the Order of the Guardians of God or risk dying.

Adam Black isn’t a civilian, and his attraction to the athletic redhead is off-limits. Letting Rachel into his life will destroy hers, but distance isn’t easy. When Rachel is targeted by the Organization, a rival secret society to his, Adam must protect her. Even if that means recruiting her to a cause she barely knows exists.

Isaac Haddad has every reason to distrust Rachel. The circumstances of her rapid, unvetted placement within the Order cannot be pinned solely on his baby brother Adam’s romantic entanglement with her. When the Fortress is attacked from within, the only logical explanation can be that Rachel is a traitor, planted by the Organization to bring the Order down.

With the rival Organization closing in, an informant leaking the Order’s secrets to the black market, and a dangerous new weapon capable of destroying whole cities unaccounted for, Rachel, Adam, and Isaac need to decide who they can trust before it’s too late.
Rated T (Teens 16+) for some swearing, violence, and some kissing.

HFN Science Fiction Romance between Rachel and Adam. Not a polyamorous. No love triangle. No cheating.