Angel is having dreams in which he is reliving his past trangressions.  He also begins to see Miss Calendar and others that he has murdered over the years.  They are affecting him so much that he eventually turns to Giles for help, who reluctantly agrees.  Giles tells Buffy that these are caused by the Harbingers who are summoning the First Evil.  Angel decides that he must die because he is not strong enough to resist the First Evil's proding to kill Buffy, so he awaits the sunrise.