Question: grimm which episode does nick get his powers back
[{'answer': 'Highway of Tears', 'provenance': [{'wikipedia_id': '42263498', 'title': 'Grimm (season 4)', 'start_paragraph_id': 51, 'start_character': 418, 'end_paragraph_id': 51, 'end_character': 434, 'bleu_score': 1.0, 'section': 'Section::::Production.:Casting.\n'}]}]