A week before Levy granted this interview, Valladares had been released, the result of a long diplomatic effort by Mitterrand. Valladares flew to Paris, where he joined his wife, Marta, and spoke with Levy. Levy had edited for Grasset ''Prisoner of Castro,'' Valladares's account of his two decades in Cuban jails, including his 40-day isolation in which he was deprived of food. Before this autumn, Levy and Valladares had never met.