 Frasier has been asked to be the visiting scholar at the University of Bologna in Italy for a 6-month tenure, and he asks Diane to come along. Although she implies that she will, she is less than enthusiastic. Frasier obviously picks up on this. She mentions Sam s fragility about the last time she left as one excuse, but she reassures Frasier that she really does want to go. In private with Sam though, she accuses him of thinking that this incident will lead to the end of hers and Frasier s relationship for a variety of reasons. Sam however is sincere in his want to see Diane and Frasier happy. So Diane plans to leave Cheers forever. After Diane s bon voyage party at the bar, Sam and Diane have a private moment together to clear the air, but it leads to a passionate kiss and embrace. However things don t continue to bed as an on-going conflict between the two rises to the surface. So Diane leaves, but before she does, Sam gives her the option of coming back to him if the "one day at a time" type relationship that he only can offer is better for her than the secure relationship with Frasier.