In a way, this episode did more for Charles and Margaret than any episode. The absence of Hawkeye leads to some fascinating character developments that serve as crucial stepping off points for the series mentality.
This episode comes at the midpoint of the series and serves as a way to alter the momentum. Antagonism in this series has been left to Margaret, Frank, and Charles and has fluctuated throughout in terms of consistency, but this is where the series became an "us vs. them" ensemble. Seeing the alternative causes Charles and BJ to work together; Margaret's past conflicts with her present.
This episode comes at the midpoint of the series and serves as a way to alter the momentum. Antagonism in this series has been left to Margaret, Frank, and Charles and has fluctuated throughout in terms of consistency, but this is where the series became an "us vs. them" ensemble. Seeing the alternative causes Charles and BJ to work together; Margaret's past conflicts with her present.