Marge is put under a lot of stress with all of her responsibilities, which include solving the problems of the rest of the family. She gradually is negatively affected by all the stress and ultimately reaches her tipping point, causing her to put herself and Maggie in danger. Her handling of the situation suggests she has poor stress management skills.
Ed's penpal sends him memorabilia from his home country. Rolf sees this memorabilia, and it reminds him of some trauma he experienced as a child. Rolf hurts the Eds in response, and they are confused as to what is wrong with Rolf.