The jellyfish changed as she moved through the gallery, becoming larger and more fantastic. Some, reminiscent of eggs, featured yellow centers suspended in cloudy white bodies. Others, with tentacles yards long, swam in never-ending circles, their arms entwined, living knotwork with no end and no beginning.

She was reluctantly impressed. The jellies were undeniably beautiful. She liked, too, that their beauty was inextricably tied to their deadliness. What made them so awesome to behold also made them efficient killers, their spectacular colorations and variety of designs being not merely decorative but entirely functional.

Still, she grew tired of them after twenty minutes and moved on after being jostled once too often by other visitors who, disoriented by the lack of lighting that made the jellyfish appear in such startling relief, neglected to notice her presence and stepped on her feet or ran into her with baby buggies. Coming full circle, she exited the exhibit very near to where she had entered.

Dismissing a display devoted to vanishing ocean wildlife as needlessly depressing, her next stop was devoted to the Outer Bays. This, she quickly saw, was essentially an enormous fish tank, stretching floor to ceiling and extending from one side of the cavernous room to the other. Behind the glass, a variety of sea life swam past: huge yellowfin tuna, sleek and sharp-eyed barracuda, a pair of sea turtles.

The star of the attraction, however, proved to be a juvenile great white shark, which she learned by reading a sign placed nearby had been successfully kept at the aquarium for some months after being accidentally caught in a fisherman’s net. Because the tank and its inhabitants were so large, it was difficult to tell where the shark was. However, the unmistakable gasps of the crowd alerted Caddie to its presence.

The shark, seemingly unaffected by its celebrity, passed by several feet above the heads of its audience. It was perhaps four feet long, a perfect miniature of what Caddie imagined a great white to be. Its black eye revealed nothing of its thoughts as it moved, its tail curving in a gentle S and its mouth open wide enough to show the teeth of nightmares. The other fish, when it approached, either swam away or formed tight clusters with their like kind.

“Apparently it took a bite out of one of the tuna last week,” a woman said to her companion.

“I think he’s cute,” said a child beside her, and the woman laughed.

“Sharks aren’t cute, honey. They eat people.”

Caddie, seeing the look of consternation on the child’s face, said, “I think he’s cute too.”

The child grinned as her mother, glancing quickly at Caddie, tried to push her way closer to the tank. Keep fighting, kid, Caddie thought.

The shark having gone, she lost interest in trying to differentiate one type of tuna from another. To her they were all big silver fish, more interesting as sushi than as living things. She hoped the little great white ate a few more of them, wished even more that she could see it do so. That would be something, she thought, imagining the carnage.