Alex Logue's abused daughter, Astra (also called Astrid), had summoned up a demon called Norfulthing that had killed Logue and his associates during an orgy. John Constantine tried to summon another demon to defeat it but failed to name and bind it properly. That demon, Nergal, killed Norfulthing and dragged Astra to Hell. This failure sent John completely insane. He was committed to Ravenscar Secure Facility. The guilt stayed with him for a long time.
During the end of the Critical Mass arc however, John succeeds in finally freeing Astra and every other child whose soul was trapped in Hell by the demon Buer. Astra then kisses the (demon) John Constantine as a thank you. Then she, together with the other children, quickly depart to Heaven.