This came to me after watching Ezri and Worf talking in Quark's while they watched Miles and Julian going over the Alamo model. The standard disclaimers apply. I'm just filling in the blanks.

Revelation

Dawn was just barely lightening the sky. Worf lifted his face to the cool breeze, catching the scent of distant cook fires and the dry smell of dust. All around him men moved quietly making last minute preparations for the coming battle. He ignored them.

Sitting with his back to the North wall of the tiny church that gave the fort its name Worf gave the impression of being lost in thought. In fact his attention was finely focused on the boy squatting on his heels a meter to his left.

The buckskin tunic, pants, and boots the boy wore were ridiculous, but accurate for the time and place. Worf shook the observation aside. Dax wanted him to see this, so there must be more to it than this elaborate game of dress up.

The boy was field stripping and cleaning his long barreled rifle. The pistol at his hip had already received such treatment. The Bowie knife tucked into the top of one boot had been honed to razor sharpness. Now the rifle was expertly broken down, cleaned, and reassembled. Each movement was precise, with no wasted motion. The boy's lean face, harder now than when Worf had first met him, was expressionless. The eyes, which usually sparked with cheer or flashed with anger were now as cool and flat as space.

Dax had tried to explain it to him. She had told him as much as she could remember of the battle of AR-568, reliving the roar and heat of hand to hand combat, the press of Jem'Hadar bodies coming over the defense wall and slamming into exhausted Starfleet troops. It had been her way of working through the horror of it, of cleansing herself of the blood and the smell and the death. In passing she had mentioned this ritual of weapons checking, done in the almost absent fashion of someone who had done it often.

Well, that was to be expected, wasn't it? They were at war, and not always the clean dance of starship with starship. It was an officers duty to be prepared, and to be familiar with his own defenses. It was what warriors did.

Worf mentally paused. It was what warriors did.

Was this what Dax had wanted him to see? Had he ignored the changes the war had brought to all of them, and continued to look at the boy as if he were still a wet behind the ears junior officer, an arrogant pest who asked too many questions? He had no time to consider the answer. With a roar the Mexicans came over the walls. Always eager for battle, Worf lost himself for a time in the slaying of holographic enemies.

Once or twice he caught sight of the boy, fighting as furiously as any Klingon. Blood stained Worf's clothes and the blade of his knife. He carved deadly space around himself, holding at bay a band of Mexicans who danced just beyond his reach. Then the boy was at his back, wearing a grin full of challenge and spite. Together they fought their way free, retreating with the rest of the forts forces for the Southern wall and the defenders there.

"Having fun yet, Worf?" Chief O'Brien called down from the battlements.

Worf glanced aside at the boy, who was still smiling slightly, eyes shining with a cold and dangerous light.

"Yes," he called back. Then, more quietly, "Shall we join the Chief?"