Of Tangible Ghosts

In this world, the Dutch never lost control of the Northeast, and France, Spain, and Chung Kuo are today's superpowers, as is Colombia. And in this universe, the ghosts of the dead linger, sometimes visible, sometimes speaking to the living. Johan Eschbach has retired from service as an agent of the government of Colombia and gone north to teach at a university in his native Dutch territory. Research is being conducted in the university's physics department - research on the control of ghosts - that is of interest to governments worldwide. And Johan is forced by his former employers to work again as a spy. When he discovers too much, he is marked for death. But at least one ghost wants to keep him alive.