Trial of the Century — Lawrence M. Schoen

At the end of BUFFALITO DESTINY, Conroy had lost his fortune and fled Earth. Reggie, his buffalito, had survived diving into a volcano, but slipped into a coma. Now Reggie is dying and the buffalito's internal nuclear furnace is growing unstable. Conroy's only hope lies with the Arconi, the aliens he ripped off to create his empire. Their help comes with a price: he has to go on trial for his crimes, against people who can telepathically tell when he's lying. Conroy knows he's guilty, but Reggie must be saved!