Both Leonard and Sheldon's mothers are coming to town to see them win an award for their joint research. The two diametrically opposed in viewpoint mothers have never met each other before. Their arrival places an interesting dynamic not only with each other, but in their dealings with Leonard, Sheldon and Penny individually and as a group. They each may gain some insight into their collective lives in the process. Meanwhile, Bernadette feels like she is mother to three children in the form of Howard, Stuart and Raj, almost like she has to channel the role that Debbie played. Especially for Howard, it's not a role he wanted his wife to be. Can Howard step up to the plate to be more the husband that he feels he should be for Bernadette?