From Present to Past - The Tigris Series Book 3

Now that the Winter Soldier is off the grid and Hydra is officially stripped of their power in S.H.I.E.L.D., Kara is finally ready to get back on her feet and set things right, both on the battlefield, and for her past. Her mental health is improving with the help of the Avengers, who have now become the only group of people she can call a family.
Though all of Hydra's secrets were released, they still have many different bases and facilities around the globe where they are looking to regroup and regrow their power. With the help of her fellow Avengers, Kara sets out to track them all down, and take them out. They discover that one of the facilities houses Loki's scepter, so they must find it and take it back.
Meanwhile, Tony and Bruce made a horrible mistake. Their mechanical creation, of whom they had named Ultron, poses yet another threat of war and destruction on mankind, and promises the Avengers' extinction. During this battle against the powerful Android, Kara runs into two siblings, who she had a damaging encounter with as an assassin for Hydra. Wanda and Pietro Maximoff. Once again, Kara is forced to face her past in a not-so-favorable way, while simultaneously proving to herself and the world that she is not the monster that she used to be; only this time, most of the other Avengers are facing the same exact self-reflective challenge.

Takes place during Avengers: Age of Ultron

All marvel characters are owned by Marvel. The only characters I own are Kara, aka The Tigris, and Eugene Adams.