Rosalind Porter's biggest mistake was love . . .

Chicago, 1950. Before Thomas Weaver broke her heart and wrecked her career, Rosalind was a leading atomic researcher. Five years on, she's alone and can barely make ends meet.

Which is when Thomas - a shattered man - walks back into her life, begging forgiveness. Rosalind would, and should, say no but for two reasons.

First, she still loves Thomas. And, second, Charlie Szydlo.

Charlie's a damaged FBI agent who believes Thomas is spying for Russia. He wants Rosalind to find evidence.

But this is a dangerous game. Who can she trust?

Thomas, who taught her how to love? Or Charlie, whose pain she yearns to heal?