2000 STEWART, I and COHEN, J. Wheelers. London: Simon and Schuster.
A novel of first contact – but with Jovians; lots of well-considered alien biology, and some astronomical puzzles are worked out.
2003 COHEN, J. and STEWART, I Heaven. Warner-Aspect, New York
Two thousand years after Wheelers, the religion has taken off – and fossilised; it must be resisted, at all costs. Many well-designed, credible alien species (as well as Neanderthals) interact in an exciting story whose philosophy is ultimately surprising.