While Buffy and the others were so distracted with Spike's newfound humanity, the Senior Partners, still very much in existence, were gathering forces to move against them. Angel and the remainder of his group, which amounted to a badly injured Gunn and an even more uncooperative Illyria, had evaded their attempts thus far. But Angel knew it as only a matter of time before the Senior Partners caught up to him.
When Gunn's condition worsened, Angel knew they would need help. But he also knew that Buffy wanted nothing to do with him. So asking for the Council's help was out of the question. He also knew that they needed to get out of L.A. Probably out of California all together. The question then became where. Where would be the safest for them to hide from the demonic forces of Wolfram and Hart?
Only one place came to mind, but it would mean returning to the country he had abandoned so very long ago. And it was following that thought that made him book safe passage for the three of them to Ireland.