Differences
The Demigod was right in her sight.
Thalia could see him clearly, creeping through the field. He thought he was so stealthy, so perfectly hidden that nothing could find him, but the Hunter could see him easily. With that came the perfect shot. She already had an arrow notched back, waiting on the string to be released. The perfect trajectory that would land the arrow right in his neck, killing him quickly, quietly and efficiently.
All she needed to do was take the shot. But she hesitated.
The Hunters behind her were staring at her expectantly, waiting for her to take the shot. Thalia could easily take the traitor out but a part of her kept her from letting the arrow fly.
She was used to monsters. Completely without humanity and full of evil, no motive beyond vengeance and a want to destroy. One arrow and they'd be turned to dust. No dirtiness, no bad taste afterwards, just business.
This was different. It shouldn't be any different but it felt that way. This Demigod, traitor or not, was a person with friends, family, hopes, dreams, motives, fears and a Godly Parent. This Demigod didn't look like a monster.
He was like her. Once Thalia looked past the moniker of enemy, she saw the half human underneath. A teenage kid, maybe the age she was. She and this Demigod were one and the same, just on different sides of the same line.
"He's the enemy," Her head murmured, "Nothing more, nothing less. He's an obstacle, one arrow and he's gone."
One arrow. All she had to do was release her fingers and this whole thing would be over. Just another causality in this Titan-God war they were all fighting. Maybe they were all just another causality, just another dead body to add to the pile.
The Demigod's still in her sight, keeping completely still. If Thalia didn't know any better she would assume he was already dead. He might already know the Hunters were there but then again maybe not. If she waited any longer he might just decide to raise the alarm and give her whole team away.
Her body decided for her. The fingers freed the arrow from it's place and it went flying, a silver streak through the night sky. It hit right where it should have, into the Demigod's neck. The boy lay still, unmoving for a whole different reason.
Her team moved forward wordlessly, confident in her shot's lethality, but Thalia stayed in place, numb to the world. She'd just killed somebody. It wasn't like monsters who would eventually come back only to be killed again. The boy would never come back, never see life again.
And it was all her fault.
She jogged back up to the front of the team. They passed the body and Thalia couldn't help but look down. Trickles of blood leaked from the puncture wound, staining the ground. Thalia looked away and felt disgust in her chest.
That night after the mission, she couldn't sleep. She lied in her cot and saw the boy's face floating before her eyes.
She lay in bed and he sat near her. They stared at each other all night, contemplating the similarities between each other.