Catechism of the Catholic Church §637 — excerpt
In his human soul united to his divine person, the dead Christ went down to the realm of the dead. He opened heaven's gates for the just who had gone before him.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.