When Aki alerts to danger, I take her seriously. She has spotted several bears that I would never have seen without her help. But, today she growls at a small stream coursing along the trail. It the water, moving along a wooden boardwalk trail section does have a bass resonance. It is dark except where it turns translucence after breaking over a damn of sticks and sparkles. After growling, the little poodle-mix drops her trail and sulks to a spot behind me. A hundred feet further up the trail, she retakes point.