Question: who is the god of the underworld in greek mythology
[{'answer': 'Hades', 'provenance': [{'wikipedia_id': '13225', 'title': 'Hades', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 5, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]