This is the best episode of the season.
Buffy comes to LA to see her dad but stops by to see Angel. While Buffy and Angel go looking for a demon Angel gets infected with it's blood and it makes him human. Angel and Buffy are as happy as anyone can get. They even do the deed. Then Angel learns that Buffy will die if he stays human. You see with him being human he wont be able to fight, and Buffy will die saving him. So angel sacrifices his humanity to safe his beloved Buffy. TPTB tell him that the time will rewind and he is the only one who will remember everything. So Angel goes home to tell Buffy the bad news. They hold eachother and Buffy cries and pleads him to take it back. They say they love eachother and then the time goes back till when Buffy first arrived in LA. Angel kills the demon without getting its blood on him.
Truely the best episode of the season. Sarah and David are wonderful and do an extraordinary job. such an "Angel" classic.