"The key to a book is the character, and his obstacles, and the idea," Mezrich said.

The idea is the most important thing, he added. Both Hollywood and the publishing industry look for projects with themes that can be summed up in a sentence or two.

"Writing a character is like acting," Mezrich said.

He described how, to get inside the head of a fugitive character in his most recent novel, he traveled cross-country for a week-and-a-half with $30,000 in cash in his backpack.

"It's kind of scary to be travelling on a train in Washington and know that the person next to you would kill you for your bag if he knew what was in it," he said.

Under the pen name Holden Scott--"my fantasy WASP name," Mezrich said--he is also the author of Skeptic and The Carrier.