The import/export business leads us to a location known as the Juju House, which may be another lead. Elias had visited the import house only a few hours before his murder.
Further inquiry reveals that Silas N’Kwane is the proprietor of the Juju House.
I manage to goad Silas N’Kwane into telling us about the unusual cultist masks. He tells us the tale of the demon priest Shakota. In a ritual, the Demon Priest has his followers beat drums in time as the moon rises. The lid slides off of the pit and the sacrifices are pushed into the pit by the will of the priest.