Hawkeye calls a number of people into the mess tent over the PA - the ones he allegedly suspects of being behind the thefts he is suspected of himself. Interestingly enough, Ho Jon, later revealed to be the guilty party, is not on Hawkeye's list - yet he shows up uninvited, just to be ensnared by Hawk's clever ploy. Note also that he had no way of knowing what the purpose of the meeting was, so we cannot ascribe to him the motive of wanting to find out how much Hawkeye knew.
Season 4. Episode 1 "Welcome To Korea". At the end of the episode the new commanding officer, Colonel Sherman Potter, played by Harry Morgan is introduced. In Season 3 Episode 1 "The General Flipped at Dawn", Harry Morgan played Major General Bartford Hamilton Steele.