Question: what episode do dean and sam meet castiel
[{'answer': "`` Lazarus Rising ''"}, {'provenance': [{'wikipedia_id': '19533905', 'title': 'Castiel (Supernatural)', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 639, 'bleu_score': 0.982060959997838, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4626800435910894199}, 'section': 'Section::::Plot.:Arrival on Earth.\n'}]}]