Morell had a long career in the CIA, ending as deputy director, but also serving as the briefer to GWBush during 2001-2 and at high levels in the intelligence side thereafter.
I'm in the midst of the book, which is well-written and reads quickly.
I want to note his apology in the book to Sec Powell for the CIA's failure to supply accurate information when Powell wrote his speech to the UN. Apologies for error should always be encouraged, and Morell's is good. He notes a number of failures of analysis on the WMD issue.