High Quality Content by WIKIPEDIA articles! "Abyssinia, Henry" is the 72nd episode of the M*A*S*H television series, and the final episode of the series` third season. First aired on March 18, 1975, and written by Everett Greenbaum and Jim Fritzell, the highly rated episode was most notable for its shocking and unexpected ending. The plot of the episode centers on the honorable discharge and subsequent departure of the 4077th MASH`s commander, Lieutenant Colonel Henry Blake (played by McLean Stevenson).