<P> The arc between FBI agent Stratton, EJ Barrett and Tony DiNozzo continues in the episode "Housekeeping". </P> <P> It is worth noting that Tony's reference to Angels with Dirty Faces is incorrect . He attributes the Priest's (Pat O'Brien) role to Humphrey Bogart, who portrayed the crooked lawyer in that film . This may have been a deliberate error due to Tony's mental state in the episode . </P> <P> "Nature of the Beast" was seen by 19.96 million live viewers following its broadcast on September 20, 2011, with a 4.3 / 12 share among adults aged 18 to 49 . A rating point represents one percent of the total number of television sets in American households, a share means the percentage of television sets in use tuned to the program . In total viewers, "Nature of the Beast" easily won NCIS and CBS the night, while the spin - off NCIS: Los Angeles drew second and was seen by 16.11 million viewers . Compared to the last episode "Pyramid", "Nature of the Beast" was up a bit in both viewers and adults 18 - 49 . </P> <P> Steve Marsi from TV Fanatic gave the episode 4.5 (out of 5) and stated that "the ninth season premiere of NCIS was slower - paced and more complicated than expected, but provided a compelling conclusion to Tony's mole hunt while setting up a new foil, and a new enemy, for Gibbs". </P>

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