The science in Lodestone is based on the concept of 'negative matter', as theorised by Dr Robert Forward, Hermann Bondi and others.
Those interested in the science aspects behind the story may wish to check out the following papers, as well as the article 'The Power of Negative Matter' by Robert Forward in the 17 March 1990 issue of New Scientist.
Bondi, H. "Negative Mass in General Relativity," Reviews of Modern Physics, Vol. 29, No.3, July 1957, pp. 423-428.
Winterberg, F. "On Negative Mass Propulsion," International Astronautical Federation, Paper 89-668, 40th Congress of the International Astronautical Federation, Malaga, Spain, Oct., 1989.
Forward, R. L. "Negative Matter Propulsion", Journal of Propulsion and Power (AIAA), Vol. 6, No. 1, Jan.-Feb. 1990, pp. 28-37.