Unbeknownst to each other, they both can walk back in time a few moments, and reshape the world's history, but it's excruciatingly painful to do that.

She is a champion downhill skier, headed for the Olympics.

Russia wants them to live together in Moscow, but they stay chaste, while they spy for the USA, feeding the Russians false secrets.  That's incredibly difficult.

They thwart murders and save Finland.

They counter and expose a USA traitor.
 
And they survive Russian assassination.

But the question is: Can they live long enough to make it home to America?

---

First in a series.  Full of twists and turns.

The sharpest and most satisfying twist comes at the very end!