The first installment was published in 1997. The second volume is due to his editors in April, the BBC said.
"Some people can write with ease in whatever circumstances they find themselves," Fry recently wrote on his Web site. "I need peace, absolute peace, an empty diary and zero distraction. ... I have a single appointment in London towards the end of January and another in Barcelona a month or so later. Otherwise, I shall be as one wiped from the map of human existence. This is how it must be. All this is a way of saying, of course, that my Twitter stream will dry up for that period."
He promised to start tweeting again once his project is complete, the BBC said.
"I shall return," Fry vowed.