Trans-Siberian Express — Warren Adler

Famous American cancer specialist Dr. Alex Cousins is sent by the President of the United States to Russia to prolong the life of the Secretary General of the Politburo. While in Russia, Cousins learns that the Soviets plan to attack China. In an attempt to silence him, the Soviets send Cousins home via the Trans-Siberian Express, the world's longest and most exotic train ride. A beautiful KGB Agent has been ordered to keep him under surveillance until the trip is over. Soon Cousins and the Soviet agent transcend their political differences and fall desperately in love.
This powerful love story, full of intrigue, will keep the reader transfixed and absorbed as the Trans-Siberian Express speeds its way across the vastness of Siberia.