'Restless': Michelle Dockery Stars In WWII Spy Drama (EXCLUSIVE PHOTOS)

Michelle Dockery is time-traveling to the 1970s for her latest TV project, "Restless." In the Sundance Channel series, Dockery co-stars in the drama opposite Hayley Atwell, Rufus Sewell, Michael Gambon and Charlotte Rampling.

In the two-part series, Dockery's character discovers her mother (Rampling) was recruited as a spy in World War II. "Restless," based on the novel penned by William Boyd, premieres on December 7 at 9 p.m. ET with part two following on December 14 at 9 p.m. ET.

Below, see how Sundance Channel describes the series and check out photos of Dockery in the '70s.

"Restless" asks the question: What becomes of your life when everything you thought was solid and certain about it turns out to be a fantastically complicated lie? This is the quandary faced by Ruth Gilmartin (Michelle Dockery) when, one day in 1976, her mother Sally (Charlotte Rampling) suddenly reveals that she has been living a double life. She is not the respectable Sally Gilmartin, but in fact Eva Delectorskaya, a spy for the British Secret Service who has been on the run for thirty years.

Eva’s story begins in Paris in 1939. Eva (Hayley Atwell), a beautiful Russian émigrée, is recruited for the British Secret by Lucas Romer (Rufus Sewell), a mysteriously alluring Englishman. As Romer trains Eva to become the perfect spy their love affair begins. When a crucial mission collapses in the USA and Eva finds herself in terrible, fatal jeopardy she knows she has no option but to run and hide forever. Once a spy always a spy. No one can be trusted. But now Sally Gilmartin yearns to end her years of restless watching and waiting. Thirty years on, the only man who can bring this about is her former lover and spymaster, Lucas Romer, now Baron Mansfield of Hampton Cleeve (Michael Gambon), and the only person she can call on for help is her daughter, Ruth. The final chapter of this epic story of love, duplicity and betrayal is about to end -- and who will pay the greatest price remains to be discovered.

Take a look at the photos below.