Question: when does stefan turn his humanity off in season 6
[{'answer': 'The Downward Spiral', 'provenance': [{'wikipedia_id': '24393478', 'title': 'Stefan Salvatore', 'start_paragraph_id': 30, 'start_character': 1808, 'end_paragraph_id': 30, 'end_character': 1827, 'bleu_score': 1.0, 'section': 'Section::::Television series.:Storyline.:Season 6.\n'}]}, {'provenance': [{'wikipedia_id': '24393478', 'title': 'Stefan Salvatore', 'start_paragraph_id': 30, 'start_character': 0, 'end_paragraph_id': 30, 'end_character': 1856, 'bleu_score': 0.6828994565009191, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10466419784889340639}, 'section': 'Section::::Television series.:Storyline.:Season 6.\n'}]}]