We didn’t see the sand shark until it was too late.

To tell the truth, I don’t think any of us really believed they existed.

Oh, we’d been warned. Mum and Dad saw the news on television and told us not to go out to the beach after school. But we always went out on the beach after school. Who would walk along the street when you could walk the beach home instead? The street was full of rubbish and car exhaust. On the beach there were shells, and sand hoppers, and sometimes even dolphins out in the waves.

So, naturally, coming home from school the next day, we turned off the street onto the beach path.

Five metres along the path, a big red sign blocked our way: DANGER! SAND SHARKS! DO NOT ENTER!

We laughed and stepped over the rope barrier. Sand sharks—yeah, right. There were plenty of sharks in the water—we knew that—they cruised along the shore, just beyond the breakers. We didn’t always see them, but we saw enough that we could tell the difference between a great white and a tiger shark. But sand sharks? That was ridiculous.

We crested the dunes and raced down the far side, like we did every day. The beach was deserted. I suppose that should have told us something, but like the other warnings, we ignored it.

Jamie and Kate kicked off their shoes and raced down to the water, splashing right into the waves. Mum would have a fit about their soaking wet school pants when we got home, I thought.

I picked up their shoes as I followed more slowly, texting my friend Ellie to see if she wanted to go to the movies on the weekend.

Maybe if I’d been paying attention to something other than my phone, I would have seen it. But it wasn’t until the shark’s massive dorsal fin sliced across the beach that I looked up.

It was speeding down off the dunes, the dorsal fin looking like a wave-sculpted bush. A heaving ripple of sand pushed out in front and to the side, like the wake of a speeding boat.

I screamed at Jamie and Kate and broke into a run, trying to get to them before the shark did. I don’t know what I thought I was going to do if I made it—I was no match for the animal—it must have been at least fifteen metres long, by the size of the dorsal fin.

Jamie and Kate either heard me or saw the shark, because they turned and shrieked. Kate grabbed Jamie’s arm and pulled, but Jamie was frozen in fear. I don’t think running would have saved them anyway—the shark raced toward them at a speed none of us could have matched. A metre from my siblings, it heaved its body out of the sand, jaws wide open, rows of razor teeth gleaming in the sun. The jaws snapped shut and Jamie and Kate were gone.

I was still racing toward them as the shark sank back into the sand and turned toward me. My steps faltered. Then I dropped my phone and the shoes I still carried, and pounded up the beach.

I could hear the hiss of sand as the shark gained on me. I hit the dry sand above high tide line, and my feet slipped as they sank in. Stumbling, I kept going, finally hitting the harder sand of the dunes. I dared a glance behind me, only to wish I hadn’t—the shark was nearly on top of me.

I flew down the path over the dunes, vaulted the rope barrier and kept going toward the street.

I heard the warning sign splinter as the shark hit it and sent it flying. I could feel the sand shift under my feet now as the shark’s wake hit me.

My feet hit the sidewalk, and an instant later the concrete buckled, sending me tumbling to my knees.

The shark’s dorsal fin was jammed into the broken sidewalk, just a metre from where I crouched. Slowly, it sank out of sight, leaving me shaking and unable to move.

A car I recognized pulled up at the kerb.

“Lynn, are you okay?” asked my mother. “Where are your brother and sister?”