A human child, born from two vampires, his birth was prophesized - "For surely in that time, when the sky opens and the heavens weep, there will be no birth, only death."
And the prophecy comes true as was foretold. Darla realizes she can't give birth because her body is dead and therefore is unable to execute the act of birth, and the unborn infant's soul within her taught her for the first time the true meaning of love - she loves this child, like she never loved anyone else. She *never* loved anyone else. Knowing he would die if he weren't born soon, Darla makes a final decision. In the dark alley behind the blown up Caritas, she shoves a stake through her heart, and as she turns to dust, on the asphalt, on the very spot where she was lying a second ago, there's now a naked human infant, alive, crying, as the rain pouring allover him. There was no birth. Only death.
Angel picks up his son and wraps him into his jacket, while Holtz is holding the crossbow aimed at him, but for some reason doesn't shoot, they share a long stare, without saying a word to one another. Angel has nowhere to escape, Holtz can release the crossbow and kill him in a flash. He embraces the child closer to him, shielding him with his own body. Finally, Holtz lowers the crossbow and Angel and Fred quickly make their way out of the alley and away into the car waiting for them.