He considered. "An Illyrion battery makes my syrynx play. I know they use it to keep this moon's core hot. Doesn't it have something to do with the faster-than-light drive?"

Mouse, there is noticeably less Illyrion in your syrynx battery, by a factor of twenty or twenty-five, than there is, let's say, radium in the fluorescent paint on the numerals of a radium dial watch. How long does a battery last?"

"They're supposed to go to fifty years. Expensive as hell."

"The Illyrion needed to keep this moon's core molten is measured in grams. The amount needed to propel a starship is on the same order. To quantify the amount mined and free in the Universe, eight or nine thousand kilograms will suffice...

"Katin, what is Illyrion?"

"Psychophysics 74 and 75. I went to the library. The best definition is the one given by Professor Plovnievsky in his paper presented at Oxford in 2238 before the theoretical physics society. I quote: 'Basically, gentlemen, Illyrion is something else.' One wonders if it was a happy accident from lack of facility with the language, or a profound understanding of English subtlety. The dictionary definition, I believe, reads something like, ' ...general name for the group of trans three-hundred elements with psychomorphic properties, heterotropic with many of the common elements as well as the imaginary series that exist between 107 and 255 on the periodic chart.'