so what happened? (spoilers , obvs)

The corpse in the basement was Mrs Jones late husband, who the priest had killed; which is why he never came back home. She thought he had left her, but he was simply killed after confessing his crimes to the priest. He and his wife were child abductors / murderers, who also had abducted the guy with the snakes - Bob Taylor - and Alex, the one Jackman tortured. They had been brainwashed and probably been through terrible physical and psychological torture too, which is why they didn't confess to neither Jackson or the police. They were, most likely, afraid that, if they said anything, that their abductors would hurt them again. And you ask why the Jones' did it? Because the Jones' were extreme religious nutjobs, that's why. Complete psychopaths. The "maze" was the necklace that Mr Jones was wearing.