swimming, eel and chase

We swam in a giant rock pool by the sea. The water was clear, turquoise and cold. It was like magic, diving like dolphin - so liberating. I swam with my family, my partner and my dog. We moved like fish in a school. After a time, someone announced they were going to reveal the giant eel in the pool. I was surprised as I hadn't seen an eel in the water, but unalarmed. We gathered around and a man tapped a rock, luring the eel to the surface. Sure enough, it came, but, at first, it seemed only to be the size of a tree snake. As we watched, it slowly revealed its full size: it was enormous; a giant, indeed. It's girth was perhaps a foot or more wide and, how long it was, I do not know, for it swam beneath the water - elusive, in and out of sight. At a guess, it may have been twenty metres or more. It was regally patterned, deep gold and black. I swore not to swim again and a man, upon hearing me, questioned why, when the water was so beautiful. I told him though the eel would not likely harm us, I couldn't risk it. 'I love my dog too much to see anything happen to her', I said. At that moment, a woman riding a very tall black horse rode past. She rode bareback and a young child sat in front of her. My dog ran after the horse and the woman slowed to reach down and raise my dog up onto the horse's back, between the child and herself. They rode away. I called out after them, but to no avail. I ran. I ran as fast as I possibly could, around the rocks and through the trees. I could see the horse ahead, but I could not gain ground. I noticed my dog was wagging her tail, enjoying the ride. I chased them through a shopping centre, pushing past shop assistants and customers. Up stairs, down stairs, around corners, in and out of buildings, but they were so fast and always ahead. Finally, I chased them right back to where the chase had begun: by the rock pool by the sea. The horse slowed and the woman alighted, bringing the child and my dog to the ground with her. I ran straight to her, gasping for breath, and hit her as hard as I could. 'You took my dog,' I cried. She looked surprised, but not hurt. 'I was just taking her for a ride', she said.