If for you a thriller is all about the plot, this series will not suit you - because the plot stands out as the weakest element in this production. A young couple returns home from St-Petersburg in a night train. When the woman wakes up, her husband has left the compartment and is nowhere to be found. On arrival he is still missing. They find him in the toilet - dead. Is it suicide? Why? Why does the phone keep on ringing? Who is the woman he talked to the night before his death? The woman, not satisfied with the suicide theory, begins her own investigation and finds a bit more than she was looking for.... OK, characters all play well, suspense is built up neatly and the series offers a nice - if somewhat rosy - image of today's Russia and it's emerging middle-class. The end, the plot come as a huge disappointment. But the build up to the plot was rewarding in it self so your time will not be wasted watching this one.