THE PRISONER.

Mikhail Khodorkovsky, once his country's richest man, has resided in ''gulag lite,'' as he calls the Russian penal system under Vladimir Putin, for six years. Since the spring, on most working days he is roused at 6:45 in the morning, surrounded by guards and packed into an armored van for the drive to court. For two hours each way, the man who once supplied 2 percent of the world's oil crouches in a steel cage measuring 47 by 31 by 20 inches. Convicted of tax evasion and fraud in 2005, Khodorkovsky now faces a fresh set of charges that add up to the supposed theft of $30 billion. In the dark of the van, Khodorkovsky tries to prepare for his trial, replaying in his mind his night reading, the daily stack of documents from his lawyers. But Russia's most famous prisoner worries too about what would happen if a car slammed into the van. (Collisions are routine in Moscow's clotted avenues.) ''Your chances of making it out alive,'' he wrote me one day this summer, ''at any speed, are next to none.'' Khodorkovsky (pronounced ko-door-KOFF-skee) has spent more than 2,200 days behind bars. He cannot receive reporters. Yet the ban has brought a revival of a dissident tradition dating back to Ivan Grozny and Prince Andrey Kurbsky in the 16th century: the epistolary exchange. For several months this year, from July until October, Khodorkovsky and I were able to conduct a series of exchanges -- as he has done with other correspondents, both foreign and native -- filtered through the hands of lawyers (who transcribe his oral replies) and avoiding the eyes of prison officials. In court, he has maintained that he fails to understand the case against him. The new indictment runs 3,487 pages but boils down to a single accusation: that the former C.E.O. of the Yukos oil firm and his deputy, Platon Lebedev, were part of an ''organized criminal group'' that stole 350 million tons of oil from their company between 1998 to 2003. The tonnage exceeds Yukos's production during the period in question. If convicted, Khodorkovsky, whose first sentence ends in 2011, could face an additional 22 years in jail. [ABSTRACT FROM PUBLISHER]