Everything will begin where season 3 left off with the basic change of Connor not drowing Angel as he is still an infant and Cordelia will not ascend. Instead Angel and Cordelia will meet on the bluff where they talk and it all becomes clear, their love for each other.
The major changes from season three will be that Wesley did kidnap Connor, but it became obvious that the prophecy was a fake and that Holtz was only manipulating the situation, to steal Connor and raise him as his own.
Wesley, having not let Justine take Connor was never in the hospital brought Connor back with proof of the false prophecy and who created it and that led to Angel killing Holtz in revenge.
That brings us back to the night of the meeting. As Angel and Cordy are meeting on the bluffs, action is happening back at the hotel. Willow having returned to Sunnydale reformed came home to find that she was not welcome so she packed her things and headed to Los Angeles to see if Angel would provide her refuge. When she arrives however the first person she sees is Wesley. They talk about what happened and Wesley agrees to take her in, but he notices something different about her. He realizes despite the fact that she was with Tara for so long he has feelings for her. He eventually will voice these feelings to her and see what happens.
Lorne, poor Lorne is now living at the hotel after the horrible incident in Vegas and his club being destroyed numerous times. He will be the helpful one around the hotel as well as the best future reading empath demon there is.
Fred will find out that her professor sent her to pylea, THe downside is She will kill him before Gunn can stop her which has put a kink in the relationship. Time will mend that though it will be hard. It will be easier because Wes didn't help her, so there is no added anger.
Lilah Morgan's mission is to find out all she can about Connor as well as running the special projects division. She also will be tasked by the senior partners to not only bring holtz back, but also recruit Fred Burkle. What happens will be left up to the players.
The evil will be the revived version of Holtz. Somehow Wolfram and Hart brought him back which somehow possessed him and he is now the beasts master. Obviously things will change, so that will be left up to the Holtz player.