Sideswipe was doing better. Still not well, Lennox knew, but apparently his systems had stabilised enough for Prime to drag Ratchet away for a brief, and no-doubt fretful, recharge. That was small comfort to the Special Forces major who considered both Sideswipe and his missing brother as much his responsibility as Prime's.

He braced himself before entering medbay, one hand against the steel wall of the mech-sized corridor. Prime might have ordered the medic to his berth, but Lennox wouldn't put it past Ratchet to slip back as soon as Optimus turned away. The last thing Major Lennox wanted now was to meet Ratchet's accusing optics. No excuses could justify his abject failure to find Sunsteaker. Not even all of the resources Lennox had thrown at the problem, the satellite scans, the police liaisons, the search parties and CIA agents he'd called in, all his efforts to track the errant bot, would placate an Autobot medic watching his patient, his friend, slipping away.

Hell, he'd even diverted search planes to scan those empty ocean coordinates, and – more of a gamble still – a Primus-damned pride-of-the-fleet submarine on the off-chance that there really was some unexplored crevice or deep trench that Sunstreaker might have been dropped into.

There wasn't. The sea floor at that point was as shallow and uninteresting as the maps made it, and what depths there were came back as empty as the surface – both to the eyes of searchers and on satellite maps timed to match Ratchet's report.

Prime had warned him, had handed over the coordinates without expectation, but it still came as a crushing blow. He'd need all the strength he could muster to avoid buckling, if Ratchet's expression offered a second.

Despite his efforts to prepare himself, he flinched when he triggered the automatic door and found himself the focus of a pair of bright blue optics. A moment of surprise and fear passed before he noticed a second pair of blue glows, and then the distinctive frames behind both – Bumblebee's vibrant yellow perched on the edge of a medical berth, Ironhide's solid black leaning against another. Sideswipe lay still on the berth between them, too far off the ground for Lennox to see his face-plates, but there was no blue glow to reflect from the ceiling tiles, no sign that the mech was awake.

"Major!" Bumblebee pitched his voice low. "You startled us. We thought you might be Ratchet coming back."

Ironhide rolled his optics before eyeing the soldier thoughtfully. "Well, come in if you're coming in then."

Lennox was too accustomed to the warrior's gruff tone to take offence from it.

"Guess I'm not the only one sneaking in while Ratchet's away."

Bumblebee gave a tired chirp, managing to put a smile in his voice, despite the situation. "Just you and me. Ironhide's actually meant to be here."

"Won't stop Ratch dismantling me if he finds I've let intruders into his medbay." There was no real malice in Ironhide's voice. If anything it was softer than usual, his optics flicking from Bumblebee down to the unconscious patient before returning to Lennox with an enquiring look. "Figure Sides here has never said no to a party whether or not he remembered it afterwards."

The human major tried to look more at ease than he felt as he walked to the berth where Bumblebee sat. Even that weak pretence fell away as the young scout lifted him to its surface, level with Sideswipe's. The invalid's armour had been polished to a gloss Lennox more usually associated with Sunstreaker. The image of Ratchet labouring with such care over his patient's outer shell because there was simply nothing else to do for him wasn't a happy one.

"How's he doing?"

He didn't expect any improvement since Ratchet's last update, but Lennox' heart sank nonetheless when both mechs stilled. Bumblebee looked at him with sad optics. Ironhide just grunted. Neither gave voice to the grim prognosis.

The looks hurt almost more than the words could. Lennox swore, pinching the bridge of his nose and closing his eyes. It was several seconds before he dared open them, letting his gaze rest on Sideswipe's gleaming shell for a long moment before looking up at his concerned companions.

"It just doesn't seem fair… That Sides has to suffer because Sunny got into trouble, I mean."

Bumblebee whirred a quiet agreement, but he tilted his head, his manner resigned. "Split-spark twins," he offered with a shrug.

Ironhide huffed a sigh through his vents. "And for all Ratch's rants, Sides wouldn't have it any other way."

"You know, no one's told me what that means yet? I mean, I saw Skids react when Mudflap went down, but…" he waved a hand towards the still form, at a loss for how to encapsulate the breadth of his question.

"It's difficult to put into human words."

Lennox was hearing that less frequently as time went by. Ironhide generally made the effort to explain when Lennox asked, even if he ignored the rest of NEST. Explaining things to humans was pretty much Bumblebee's job description, together with guarding the kid, and Optimus was patience himself when a spare moment presented itself. Even so, he sometimes felt there were gulfs of understanding, the whole concept of Cybertronian twins amongst them, that simply couldn't be overcome. It wasn't going to stop him trying.

"They're telepathic with each other, right?"

"That's part of it," Ironhide grunted.

Bumblebee shifted on his aft, looking down at Sideswipe with a quiet whir of regret. "It's more like… you know how you always have a quiet voice in the back of your head, second-guessing your decisions or speculating about the people around you, or, I don't know, wondering what's for dinner?"

Lennox nodded, intrigued.

"Sunny and Sides are that little voice for each other," Bumblebee said, spreading his hands to either side as if trying to express how inadequate the explanation was. "Sometimes it might go quiet for a while – if they're a long way apart or one is in recharge – but they're always there, inside one another."

"How do they stay sane?" The question burst out of him before he could censer it. He was expecting Ironhide and Bumblebee to react with anger, not with whirring laughter. It seemed the initial premise of that question was giving them problems.

Ironhide stifled his laugh with an effort, one hand thumping down on the berth beside him.

"It's just what twins are." He looked down, and the smile faded. "But imagine that voice screaming inside your helm."

"And if it was gone for good?" Lennox felt the blood drain from his face, really understanding for the first time. "You're saying that if Sunstreaker dies, it's not just like losing a brother. Sideswipe won't just suffer…"

"It'll be half of Sideswipe dying," Bumblebee whispered. He shuffled forward on the berth, leaning forward to rest a hand on Sideswipe's arm. "It'll be Sides himself."

Ironhide rocked a little, his engine grumbling. "He wouldn't survive."

Lennox climbed to his feet, pacing for a few seconds before dropping back down on the cool metal surface of the med berth. Skirmishes against the Decepticons played out in front of his eyes: all the times Sideswipe had thrown himself into the forefront of battle, latterly with his brother by his side. It was too easy to picture one or both of them lying here damaged, in a thousand different scenarios where saving a single life would be challenging enough and asking to save two just too far beyond reach.

"How the hell have you kept them alive this long?"

"That's a question Ratch asks himself every time they end up in here." Ironhide grunted. "He's got a lot to do with it. Most medics wouldn't even try to save a pair of damaged twins. Four pairs in five didn't make it past their first vorn – and that was before the war fragged up everyone's lives. But even Ratch doesn't claim full credit. Megatron ordered twins hunted down, back in the early days. Said they weakened the species." The hard note in his voice softened, a fond note entering it. "This pair are fighters. They took one look at the Decepticons and decided they weren't going down easily."

Bumblebee warbled an agreement, settling back where he sat on the berth. "They've kept themselves alive. And lived every moment of the vorns they've had." He smirked. "Drove Prowl wild."

Ironhide shook his helm ruefully. The big mech let a smile ghost across his face-plate, his hand falling to rest of Sideswipe's still shoulder.

"They've always been a handful. Prowl was the only one who could ever stay one step ahead of their tricks."

"He had plenty of practice with Jazz." Bumblebee whirred out a quiet laugh despite the sorrow that crossed his expression. He looked down at Sideswipe, shaking his head. "Wish we had Prowl here now. Jazz too."

Ironhide grunted, patting Sideswipe's shoulder before moving a little closer to Bumblebee instead. He reached out to run one finger down the young scout's helm. "You and me both, kid. You and me both."

"Who's Prowl?"

Not for the first time, Lennox suppressed his annoyance when the two mechs startled. The presence of a single, small human must be easy to overlook, all the more so when the Autobots in question were sharing the familiar, melancholic look that came over them on the rare occasions they spoke of distant friends. Most of the time they avoided such discussions, whether through taboo or just wary of tempting fate, Lennox couldn't be sure. Usually he wouldn't question the quiet, regretful comments. Here and now though, in the depths of night and with two of the Autobots he knew best, he couldn't help asking.

"I've heard the name before – from you, from Ratchet and Prime. No one's seemed that keen to stop and explain though. He's important to you?"

Ironhide grunted, looking away and letting his hand fall away from Bumblebee. "To us? I'd say Prime's lieutenant was pretty important to the whole fragging planet."

Lennox's look of curiosity faded into a frown. "Thought that was Jazz?" he asked cautiously. This felt like dangerous territory. Both Bumblebee and Ironhide had tensed, their expressions more than a little grim.

"Jazz and Prowl did a lot of things together." Ironhide sighed, air pushed out through his vents. He leaned down a little, his shear bulk looming over Lennox as his blue optics focussed on the human. "We don't talk about it a lot, Lennox, but you should probably know. Optimus had two lieutenants – back in the day. Technically Prowl was our second, Jazz was our third, but the way they worked together… well, sometimes I wondered if even they remembered that."

"The two of them pulled off things even Prime never dared to believe possible," Bumblebee added, his head tilting a little to one side, and his voice wistful.

"One of the most unlikely partnerships I've ever seen." Ironhide shook his head in mild disbelief. "And one of the best." He vented another sigh, this one longer and lower. "The stories we could tell you, Lennox. The stories the Decepticons could tell you! Those two mechs could be deadly when apart, and either was strong enough to take the weight when Optimus needed a shoulder to lean on. But together…. The Autobots follow Prime, Lennox, without hesitation or doubts. Optimus Prime gives us vision, a dream to aim for and a reason to keep going, but sometimes I can't help but wonder if Prowl and Jazz were the backbone that kept us marching. Kept us strong all along."

There was silence for a few moments, and it wasn't a happy silence. There was something more going on here, and with Ironhide in an unusually talkative mood, Lennox intended to get to the bottom of it. He leaned back, his legs stretched out in front of him and his arms behind him to support his weight against the metal tabletop.

"So… from the way you're talking, I guess I won't get to meet this guy?"

"You might." Bumblebee's wistful, hopeful offering overlapped with Ironhide's blunt "No."

Lennox stayed still, careful not to draw attention as the two mechs exchanged glares above his head.

"Prowl might still be on his way. Just because it's been a few years… We don't know how far away he was. His team might have been searching halfway across the galaxy! Just 'cause he's not here yet doesn't mean…" Bumblebee trailed off into silence. He shook his head, engine whining after his outburst. His vocaliser reset with a click and he cycled his optics before trying again. "Prowl wouldn't ignore Prime's call, 'Hide. He'll come if he can."

"I ain't denying that, kid." Ironhide's optics slid to one side, his voice quiet.

Bumblebee stilled, the regular whirr of his vents hitching for a moment. He ducked his helm a little, blue optics intent on Ironhide's face, and edged closer.

"You know something," he accused. A few seconds of silence dragged by before Bumblebee's shoulders slumped, his optics dimming and the plating falling flat against his back. Ironhide looked up with reluctance, his own broad shoulders hanging heavy. His optics flicked to Sideswipe and then to Lennox, but his attention was all on Bumblebee as he went on.

"Prime picked up a message a few orns back, Bumblebee. Sent ahead by a couple of incoming Autobots."

Bumblebee studied his commander's face, the door flaps and elements of superfluous bodywork trembling on his back. "Who?"

"Wheeljack and Bluestreak. They're six months out still."

"Blue's coming?" For a moment, Bumblebee brightened, but then a distressed click escaped him. "But… but they were searching for the AllSpark with Prowl."

Ironhide nodded grimly. "There wasn't a lot of detail. Guess they weren't sure the comms were secure. But they said they got separated and hadn't heard from Prowl since. They gave a date reference."

There was a burble of Cybertronian, presumably naming the day, and all the remaining animation drained from Bumblebee.

"Mission City," the scout said flatly and then his face dropped into his hands, a thin keening sound rising from him. Ironhide swore, voice soft and full of pain, before throwing an awkward arm around Bumblebee's shoulders.

The grieving 'bots took all of Lennox's attention, so much so that he didn't even notice Sideswipe stir on the berth beside him. Ironhide didn't miss it, his spare hand going out to stroke Sideswipe's helm in a surprisingly gentle gesture, even as his other arm held Bee against his side.

The big weapons' master glanced in Lennox's direction as the human leapt to his feet, mouth open to ask about Sideswipe. His sorrowful expression killed the exclamation on Lennox's lips.

"Ratchet says he's been half-awake a couple of times today, still delirious. He should recharge if he can." He looked down at the ailing warrior, his voice firm as he snapped out a command in Cybertronian.

Sideswipe said… something… the usually warm voice flat and robotic, the response seemingly automatic. Ironhide sighed and shook his head. A moment later the palm-sized tablet-come-smartphone in Lennox's breast pocket beeped. He fished it out, momentarily grateful for the distraction, until he saw the day's third set of coordinates listed in the Cybertronian data feed. Ironhide had marked this one with the same warning flags as the others – off-shore, below the ocean floor. Sideswipe's coordinate system seemed to be drifting with time, just as it had between the first two reports. It still wasn't close to being a useable guide to their search.

Disappointed, Lennox nodded an acknowledgement up at Ironhide. His wary eyes scanned the two conscious Autobots. Bee seemed to be pulling himself together, quiet keens still spilling from his trembling form from time to time, but suppressed for Sideswipe's sake.

The younger Autobot shook his head, glancing down at the patient, before looking up with over-bright optics. "Prowl and Jazz… They really were bonded then?"

Ironhide grunted, not moving his arm from the scout's shoulders, but not meeting Bee's optics either.

"Guess only Prime knows for sure. And Ratchet maybe. They're still not talking. But it's a Pit of a coincidence."

"Bonded?" Lennox flinched as two pairs of optics snapped down to him. The Autobots eased apart, Bumblebee straightening up, Ironhide's arm dropping away. The thin wails from Bumblebee had subsided entirely now. The silence was split only by an unconscious murmur from Sideswipe, the red warrior's helm tossing from side to side despite Ironhide's soothing touch.

Ironhide and Bee shared a look before the elder 'bot spoke, voice gruff. "Sometimes a pair of 'bots can choose to form a link between their sparks."

"Like Sunstreaker and Sideswipe's?"

Bee's vocaliser whirred in something that might have been disagreement. Ironhide tilted his head, scowling.

"Not really. But similar."

"That doesn't make a whole lot of sense, 'Hide."

"A whole lot of things about bonding throw common sense to the Pit." Ironhide shook his head. "There are advantages as well as the disadvantages. But, yeah, it's pretty rare since the war broke out because of the whole double jeopardy thing." He looked down at Sideswipe. There was a faint glow in the 'bots optics now, but no sign that he recognised his surroundings. A murmur of Cybertronian spilled from him, but judging by the sad frown on Ironhide's face, it was the fever talking, not Sideswipe's rational self. "It's not quite as Primus-damned-certain as with split-spark twins, but you sure don't see a lot of broken-sparked bondmates walking around."

Lennox nodded grimly. He'd seen the Autobots grieving Jazz after the Mission City battle. From the way they were talking, they'd known even then that they were most likely mourning the lost sparks of two officers rather than just the one.

"So that's why this Prowl doesn't come up much in conversation," he noted, more for something to say than anything else. He knew better than to offer false comfort to his fellow warriors. "I was kind of confused when I heard Sunny and Sides talking about him last week."

Ironhide's frown was redirected, fixing Lennox in its thousand-watt glare.

"The Twins were talking about Prowl?"

"Well, if you'd got that message…?"

Ironhide shook his head, the gesture emphatic. "Prime's not advertising it yet. Not until 'Jack and young Blue are close enough to give us details." He hummed thoughtfully, gazing down at Sideswipe. The crimson shell was shifting, the occasional mutters growing louder as his optics flickered. "I wouldn't put it past this pair to hack the base coms though. That might have a lot to do with how out of sorts they've been lately."

"They were friends of Prowl's?" Lennox ventured.

A rumble of something like laughter vibrated Ironhide's frame. "'Friends' might be the wrong word. But, maybe… Yeah, I guess they were kind of fond of one another, in a driving each other to the Pit sort of a way. As front-liners, they answered to the tactical office. Prowl was their immediate commander for a long time. The mech tried to find them in that last panic, when Cybertron fell. They'd already found their own way off world."

He leaned forward as he spoke, putting a little weight on the hand he'd rested on Sideswipe's shoulder. The red front-liner had started to become more active, tossing and turning, his optics brighter.

"Rest easy, youngling," Ironhide murmured in Cybertronian before switching to English. "Sideswipe, you need to stay calm." He paused, leaning closer and taking both Sideswipe's shoulders in his hands. "Can you hear me, youngster? Sideswipe? Where's your brother? Where's Sunstreaker? Where's Sunny?"

Lennox held his breath and Bumblebee stilled his vents, both of them straining to hear any answer, desperately hoping Sideswipe could provide the information that had eluded them all.

"Sunny…" Sideswipe murmured the name in English, his response to Ironhide dazed and incoherent. "Hurts… it hurts… can't breathe. Got to find… But I'm here, and where…? Prowl? Prowl could find us… help us." The mech's incomprehensible rambles faded into silence but Ironhide and Bumblebee clamped their hands to their helms, and Lennox mirrored them as a surge of static burst from his radio earpiece at astonishing volume. Scowling, massaging below his ears to ease his aching jawbone, Lennox scrabbled once more for the tablet computer he'd only just put away.

- Prowl? Prowler? You gotta help… Sunny… it's cold and it's dark and it's damp and it hurts. It hurts… Sunny? Where…? Where are we? Prowl? Help… please… help us… please… -

The translated Cybertronian broke up into random symbols, the automatic algorithm NEST had been provided with failing as the delirious mech slipped back towards recharge. Ironhide vented hard. The weapons mech had taken a few steps backwards in the face of the radio bombardment. He reclaimed them, his expression strained. Looking down at Lennox, his vocaliser whirred, struggling for words.

Ratchet didn't give him a chance to find any. The medic appeared from nowhere, brushing past Ironhide to reach his patient, fussing over the prone mech for a long minute as he ensured Sideswipe was once again resting comfortably. There was silence in Medbay. Ratchet glared, his body hitched up into a towering rage that couldn't quite belie the tired slump of his shoulders.

"Well?" he demanded.

"We were just talking, Ratch." Ironhide's hands came up defensively in front of him. Bumblebee was already slipping towards the door, quite willing to leave the senior bot and the NEST major in the lurch. Ratchet's arm snapped out, an extended finger pinning the scout in place, even as his optics did the same to the larger Ironhide.

"Talking?" Ratchet vented hard. His gaze flicked towards Lennox before returning to Sideswipe. "About Prowl?"

"I wanted to know who he was," Lennox volunteered. Wary as he was of Ratchet's fury, he was pretty sure the Autobot wouldn't hurt him. He was less certain Ironhide and Bumblebee could say the same. "I'd heard the name."

Ratchet's aggression drained away. Only the weariness remained as he dropped into the chair beside Sideswipe's berth. The look he turned on Ironhide was heavy with exhaustion and sorrow. "You should've known better. I left you here to watch my patient, not upset him." He dropped his face into his hands. "Primus, but I wish we had Prowl here right now. If anyone could figure this out and find Sunny…" He shook his head, looking up tiredly. "I'm awake now. I'll sit with him. Get out."

There was no vehemence behind the words, but it was an order nonetheless. Ironhide nodded, scooping Lennox up as he followed Bumblebee to the door. The human didn't complain, letting himself be carried and leaving both medic and patient in peace.

Something was wrong. He'd been sure of it even before the call. The twins had never given up on anything so easily in their lives. He was ninety-eight point nine percent sure they wouldn't start with him.

And then the forlorn wail, crying out across the cold vacuum with a desperate plea for aid.

Even when he heard it, he hesitated.

Was he ready for this? Could he set foot on the world where Jazz had bled and died? Would he be able to face what waited for him, or would every vent remind him of that loss? Could any world be left untainted by the energon that seeped into its organic soil and rose in dark miasma through its over-thick air?

He wasn't ready. He knew it in his spark, just as he'd known it when he entered the system. He wasn't strong enough, and might never be. But Prime waited for him, and Ironhide, and Ratchet, and while he longed to see them, he knew that he would be committing himself. Once Ratchet saw him, there'd be no chance of giving in to the temptation to rest… if that had ever really been an option.

His spark pulsed, and he felt a flutter against it. He should calm himself. He couldn't, his turbulent emotions threatening to override his processor.

He'd run out of time for uncertainty: something was wrong. Maybe, before the call, he'd have thought it was a trick – the twins' final effort to lure him into a response. Afterwards… no. Maybe, just maybe, the need was actually as desperate as Sideswipe seemed to think.

That wasn't a chance he could turn away from.

He wasn't ready. But he had no choice.