New York detective investigator Arthur receives a mysterious letter, with an air ticket and an encrypted message, from his university professor, a Ukrainian, with whom he had not communicated for many years. Trying to puzzle it out, Arthur learns that the Professor is dead, having allegedly committed suicide, and unknown people are hunting for the Professor’s daughter, Lesya. Arthur flies to Kiev to unravel this enigmatic tangle and to help the daughter of a man who played an important role in his life many years ago.