Black Widow by Kelly Thompson

Natasha Romanoff has been a spy almost as long as she’s been alive. And she’s never stopped running, whether she was working for the good guys or the bad. But now she is…retired? And enjoying a perfect life she never dreamed she could have. But if you scratch the surface, you’ll find something very wrong lurking beneath this new world — and a woman like Nat just can’t help but scratch. As her happy existence ends in heartbreak, Nat must make a fresh start! Back in San Francisco, she finds new allies…and dangerous enemies, including the scheming Apogee and the enigmatic Twins. But worst of all is the Living Blade — the one skeleton in the Widow’s closet that she hoped would never come back out!