Amongst St Patrick's major exploits was his defiance of royal authority in lighting a fire at Slane on Holy Saturday. This led to an unsuccessful visitation by the instruments of King Laoghaire (Leary); the vital clash did not however occur until Easter Sunday. It took the form of a contest of miracles performed at Tara before the king by his druid Lucat-Mael and by Patrick. The saint was consistently able to surpass the druid and eventually destroyed him. The particular miracle featured in FW involves the darkness brought over the land by Lucat-Mael's invocations. Requested to dispel it, he announced that he would be unable to do so until the following day. Patrick caused it to vanish instantaneously. As the sun shone forth once more, all the people cried out glorifying Patrick's God.

McHugh, Roland / The sigla of Finnegans wake