
The recap below contains plot spoilers about Episode 16, "Once Upon a Time." If you haven't seen "Once Upon a Time" yet, you can watch the full episode online.
No. 6 faces ruthless interrogation, taken to the extreme degree, in an effort to make him reveal why he resigned from his top-secret job.
One man must break, and for the loser, it is the end. The choice lies between No. 6(Patrick McGoohan) and No. 2 (Leo McKern). In taking the ultimate step in putting No. 6 through the degree absolute, No. 2 is well aware of the personal risk he is running.
An electronic process prepares No. 6 for the ordeal that lies ahead -- a week or more of savage, relentless interrogation, with only one answer required from him: Why did he resign?
He knows there is no way out, knows his mind is being regressed as No. 2 takes him through the seven ages of man taking him back to babyhood, early childhood, growing up, school days, his first job, the war years, and the top-secret job he had until the day he resigned.
No. 6 relives his life in the macabre charade. His replies to the questions come automatically and truthfully, but the closed secret in his mind remains locked. However innocently phrased, there is no answer to the question "Why did you resign?"
Day lengthens into night, night into day -- and day after day the ruthless, penetrating questioning continues, with one man's will pitted against the other's.
They sweat, they tire, they reach near exhaustion. The mental battle becomes a physical fight, but each is unyielding.
One has got to break, and breaking may well mean death.