He walked alongside them and watched.

Unseen to those he observed, Zack bit out the first syllable of a futile warning as a monster, shrouded in the brush, shot a needle-thin projectile from its tail into the group as they walked. The stinger sailed through the air with dangerous precision and embedded itself eagerly into Tifa's upper arm.

At her surprised cry of pain, Cloud and Barrett reacted immediately. Barrett turned with a staccato shout and sent gunfire into the bushes. Cloud's hand wrapped securely around Tifa's elbow, holding her steady as he swiftly removed the spike and examined it while muttering to her softly. Aerith and Red XIII dropped into defensive stances, glancing around warily.

A wounded whimper came from the thick overgrowth as Barrett's bullets hit home. Zack jogged a few paces to get a better look at the creature. It wasn't anything that he was familiar with, and it was quite dead.

He whirled upon registering Cloud's grunt to see his friend catch Tifa as she suddenly went limp. To anyone who didn't know him well enough, Cloud would have looked intent and collected. But Zack saw the concern etched into the set of his friend's mouth and the draw of his eyebrows. Tifa's hair flowed over Cloud's arm to pool on the ground as he lowered her to rest across his lap.

Aerith was by their side immediately, rifling through her pack. Her green gaze was hard as she stared at the dark lines spreading quickly up and down Tifa's arm, the sinister tracks originating at the pinprick of the monster's stinger.

"Probably a fast-acting poison," she murmured, pulling out an orb of materia.

"Should I grab an antidote?" Cloud asked, his voice low and urgent.

Aerith, ever the intuitive caretaker, shook her head. "This will be stronger."

Zack looked on, mesmerized. He had seen many sides of Aerith, but he was always amazed by her abilities in battle and healing. The glow of magic lit her features as she focused on Tifa's wound. The smile that began to curve her lips stole his breath as the light faded, taking the black venom with it.

Cloud exhaled a barely-there sigh. As Aerith put the materia away, he adjusted Tifa and pulled her closer into him.

"Tifa?" he called quietly in a tone that Zack had never heard before. "Tifa? You with me?"

Zack crept a bit closer, his attention split between Aerith and Tifa. He was absently aware of Barrett casting a worried shadow over Cloud's shoulder and Red XIII watching solemnly from a few feet away.

"Should I give her a potion?" Cloud asked without looking up.

"I don't think she'll need it," Aerith replied calmly. "Give her a second."

Sure enough, Zack huffed in relief when Tifa's eyes sluggishly opened. She lifted her head slightly from where it rested against Cloud's shoulder but didn't make any move to rise.

"Cloud?" she whispered.

"Hey," he answered, his expression thawing into a look that was as soft as Cloud ever got. "How do you feel?"

Tifa grimaced.

"Tired," she whispered. Her palm dropped against the ground in front of Cloud's knee and she attempted to push herself upright. Almost instantly, her arm trembled and buckled. Cloud's hold on her tightened in response.

"Why don't you take it easy and get some rest?" Cloud suggested in a way that left no room for argument. "We're close to the next town. I've got you."

Zack suspected that lucid Tifa would have protested vehemently, assuring the group that she was perfectly capable of going the distance. However, recently-and-severely-poisoned Tifa merely nodded drowsily, closing her eyes and relaxing into Cloud's chest.

Aerith stood and brushed the dirt off her dress from where she had kneeled on it. Zack watched her watch Cloud as the latter stood with Tifa in his arms and trekked smoothly onward. Aerith's beautiful face was pensive in a sorrowful, wistful sort of way. There was never a moment when Zack didn't wish that he could reach out and touch her or that she could hear his words, but there were times when those desires strengthened into a veritable ache inside his chest. He would consider leaving during those times, as he could choose to be elsewhere, if he wanted—in a separate plane of existence entirely—but those were also the times when he could never bring himself to depart. And when he did go, he never stayed away for long. Aerith had this gravity to her and Zack was utterly helpless against it. He always had been.

Tracing every line of her face, Zack searched for jealousy. He would never begrudge her for moving on, especially if her attentions fell on Cloud, whom Zack adored, but that didn't mean it wouldn't hurt. He wanted every happiness in the world for her, and he had already processed the fact that such happiness would probably entail settling down with another man at some point in the future.

More specifically, Zack had confronted that reality when Aerith and Cloud had met in the church. He had been contentedly watching her tend to her flowers when his old friend had plummeted into said flowers much in the way that Zack himself had, once upon a time. As he watched her draw a stoic, unsettlingly different Cloud out of himself, Zack had resigned himself to a strange mix of longing and gladness at the thought of his two favorite people finding solace in each other.

And then he had seen Cloud reunite with Tifa, and Zack had realized that for Cloud, there would never be anyone else but her.

But as he trained his eyes on Aerith, he didn't see envy in her. Rather, he saw every emotion weighing heavily in his chest reflected on her face. Her hand slowly came up to finger the edge of the pink ribbon securing her auburn hair.

Longing.

She wanted what was in front of her, Zack realized, but it wasn't Cloud. It was the indescribable connection between Cloud and the woman he carried.

Zack burned with the impulse to reach out and clasp her hand, to assure her that he would always be there to catch her and hold her, but the invisible distance separating them stayed his hand. Once again, he felt the acute loss of so many moments that had been taken from them.

That day long ago, on the edge of Midgar, each bullet wound had been another wish unfulfilled, left to dilute into nothingness in the coming rain.

As Aerith began to move onward, so did he—an ever faithful sentry by her side.