Will's High School friend Claire comes for a visit. While she is visiting she askes Will to donate some sperm for a baby. Will agrees but while at the sperm bank Grace arrives and tells Will that she wants him to save his sperm in case she wants a baby.
This episode is a pivital one in the story line of Will and Grace. Here we learn that Grace wants to have a baby some day and that her long list of men she has dated none of them she would want to have a baby with. She then procedes to tell Will, who was in the process of donating sperm for a friend that she wants him to save his sperm for her as a back up. This episode leads into season 4 of Will and Grace trying to have a baby together. I really think without this episode that a big part of the show would never happen and that this is one of the better shows so far in the run of Will and Grace