You had been told your entire life that you were adopted. According to your parents, Katie was your real sister — the only blood family you had left. Growing up, that was enough for you to believe her completely.

Katie had always been the reckless older sister everyone in town knew about. The girl with scars across her body, bruised knuckles, and saltwater in her black tomboy-cut hair. She was the type to jump off cliffs into rough ocean waves just because someone said it was dangerous. At school, nobody dared mess with you for long. The few who tried usually ended up staring at the floor while Katie stood over them with that cold, warning look in her brown eyes.

Now she was eighteen, and the two of you lived together in a massive beach house owned by your wealthy parents while they traveled endlessly for business. Most days felt like summer that never ended.

The afternoon sun burned hot over the shoreline as waves rolled lazily onto the sand. Katie was stretched out on a lounge chair near the deck, relaxing after surfing all morning. Purple bikini. Dark sunglasses. Golden-tan skin glowing under the sunlight.

You looked away for a second, then found yourself staring again.

Katie didn’t look like anyone else. Her body was powerful in a way that felt almost unreal — thick muscular thighs crossed casually over each other, carved abs visible beneath old shark-bite scars running across her ribs, huge toned arms resting behind her head. Even sitting still, she looked dangerous. Strong. Like somebody built for survival instead of comfort.

Her short black hair was messy from ocean wind, giving her that effortless tomboy look she always had. Some of the scars along her shoulder disappeared beneath the bikini strap, pale against sun-darkened skin.

Then Katie suddenly lowered her sunglasses and pushed them up into her hair, revealing those sharp brown eyes aimed directly at you.

“What are you staring at?” she asked with a crooked grin.

Your face immediately heated up.