"What do you mean, he's gone?"

Boulder placed his book back on the shelf, never taking his optics off of the racecar.

"I mean he's not in his room, and he's not down here. He couldn't have gotten upstairs without us noticing...Right?"

The three bots were all up the elevator in an instant, searching the garage for their teammate, but he was nowhere to be seen.

"You don't think he left the island, do you?" Salvage asked.

"If he did, High Tide would be the one to-"

Boulder, come in!

Dani's voice came ringing through the comm unit. Get over to Walnut and Sixth. A sinkhole opened up and Chase fell in!

"Understood." Boulder informed as Graham came sliding down the pole to join him. "Blurr, come with me. Salvage, stay here in case Heatwave comes back and contact High Tide to ask him if he's seen anything."

"Yes sir!" Salvage replied with a salute, and then Boulder and Blurr transformed into vehicle mode.

"Heatwave's missing too?" Graham worried.

"It's a long story. Let's make sure Chase is alright first..."

_________________________________________________________________________________________________

Chase? Chase, come on, wake up...!

Chase could hear his partner's voice speaking to him, but it was distant and murky. He struggled to find it, while also trying to remember what had just transpired. His processor slowly pieced it together; they'd been driving down the street when it had suddenly broken open and they'd both plummeted into the darkness. He must've hit something other than the dirt underneath, because his helm was pounding like a drum.

The waking world snapped back into focus in a flash, and he gave a gasp as his optics opened and stared out into the darkness.

"Whoa! Easy Chase, easy..."

"Ch-Chief..." Chase rasped, his optics searching the murky brown haze around him, and bubbles occasionally floating into his view told him he was at least partially submerged in dirty water. "A-Are you harmed?"

"Some bruises from the seatbelt digging into my shoulders, but otherwise fine... What about you? You were out for a minute."

Chase shifted again, his chassis creaking under the water. "...Minor damage..."

He tried to get to his feet, but found something heavy and stiff holding his legs to the floor up to his knee joint. "...But I'm afraid my legs are pinned under debris, and my current position prevents me from digging myself out."

"Don't worry, we'll think of something..."

Chief looked up as light appeared from above the water, and Chase struggled, pushing up on his hands into the mud and finally getting his helm above the water.

"CHASE!" Blades hollered from above, and Chase spat water from his mouth before making out the crack in the ground they'd fallen through above them. "Are you alright!?"

"Not exactly..." Chase admitted through the comms. "My legs are pinned, I cannot get free on my own."

Don't worry, we'll get you out. Blades informed, Boulder, hurry. We need to widen the opening.

No. Too risky. Graham argued, If we try to make the hole larger, then we run the risk of caving the roof in on top of them.

Well we can't just leave them there!

Chase sighed, trying to think of another solution but coming up with none. "...Blades, send your tow line down into the tunnel and take Chief Burns back up to the surface."

Chief placed a hand on the monitor, his eyebrows furrowing. "Chase, I'm not leaving you down here all by yourself."

"The water is only getting deeper as it fills up this part of the tunnel, and my cab will run out of oxygen eventually. I do not require oxygen and can remain here until a solution is found...Please."

Chief sighed, and then unstrapped his seatbelt. "I don't like this..."

"Nor do I, sir. But your safety is more important than my comfort."

"...Stay safe."

"Of course, sir."

Chief gasped as Chase's windshield opened and the chilly water came rushing in. He was knocked back against the back, but then swam out and up towards the light. He gasped as his head broke the surface, looking at his partner's helm trying to stay above the surface to keep an eye on him.

"Lowering the winch!" Blades hollered, and after a few seconds, the hook came splashing down into the water.

Chief swam over to it and grabbing tightly to the rope. "We'll be back for you, Chase!" He assured as the winch began to lift up once more.

Chase gave him a nod, before the water swallowed his helm once more and the rescue bot was completely submerged. The police bot's helm was beginning to spin, and he allowed himself to rest it back down on the bottom, closing his optics to rest for just a few cycles.

Chief clung to the rope as it pulled him closer and closer to the light, and winced as he finally broke free into the freedom of the surface.

"Dad!" Graham helped Chief away from the crack. "Are you okay?"

"Fine, son... Let's just get to work finding a way to get Chase out of there." Chief grabbed the hem of his shirt and wrung out some of the dirty water.

"Not to mention we still need to find Heatwave." Boulder informed. "We checked his room and he was gone."

Did you check the bunker tunnels? Cody asked through the comms. He's been spending a lot of time down there.

Not yet. Salvage informed, Blurr and I will take a look.

"Be careful," Chief informed, "The tunnels may all be at jeopardy of collapsing..."

________________________________________________________________________________________

Heatwave was well aware of the tunnels lack of structural integrity. He didn't remember how he wound up down there, but he was here, and something was pulling him deeper into them... An odd smell.

It wasn't the smell he and Blades had picked up the other day; that smell had been identified as Heatwave himself. The firebot had scrubbed himself down helm to heel strut, but it still persisted, so since he and Blades were the only ones whose olfactory sensors were picking it up, he just left it alone.

No, this smell was different, and he wasn't going to stop until he'd determined its origin and made sure it wasn't harmful to humans.

As the tunnel dipped downward, he found himself stepping into water that was steadily getting deeper. His feet squished into the mud, but never more than a few inches as he trudged through. The smell was getting stronger, which meant he was getting closer.

Heatwave, do you copy?

Salvage's voice crackled with static as he tried to contact the firebot, and Heatwave paused for a moment to answer. "I'm here, Salvage. What is it?"

Where are you? We couldn't find you at the Firehouse, so-

"I'm on a mission. Something smells down here and I'm going to make sure it's not hazardous."

Since when do you bother investigating bad smells?

"Salvage."

Sorry... Just be careful, alright? You don't want to get trapped like Chase is.

"Chase is trapped somewhere?"

One of the tunnels collapsed and he-

"I'm going to help him. I'll keep you posted."

But Heatwave, Chief Burns told you not to-

Heatwave blocked out the rest of the transmission; he'd deal with the Chief's wrath later. He placed the uncovering of the scent's source in the back of his processor for now, focusing on finding his teammate. The murky water continued to increase in depth, until it was splashing up against his underside, his neck stretched forward and head held low as he searched the walls of the tunnel for clues.

The sparkling evidently did not like the cold of the water seeping through his plating, squirming and making the Firebot wince as they pushed on other parts of him in an effort to get away from the cold. "Just a little rescue op, nothing to worry about." Heatwave assured.

He shuffled his feet along the bottom, beginning to feel other debris than just the muddy floor of the passage. He followed the debris path until his lights lit up a large obstruction in front of him. Rocks, wood, mud and asphalt formed the pile, and water was spraying out through the cracks, implying that once removed, a flood of water would come rushing into this side of the cavern as well.

Just the same, it would need to be moved in order to continue, and that odd smell was conveniently stronger in the direction he was going.

Heatwave started at the top, tugging pieces of rock and asphalt out of the way and tossing them aside. As he removed the debris piece by piece, others were knocked loose by the water pushing its way through. His feet tugged boulders free from the edges of the bottom, and slowly but surely the obstruction began to be washed back Heatwave's direction. Heatwave stood fast as he felt it brush past his legs and the trickles of water became streams.

After a few minutes, he stepped aside, watching as nature took over the cleaning up and large chunks of the wall disappeared back the direction he'd come and then being sucked down a neighboring tunnel that sloped downward. It then shuddered, and as the water on the other side receded, Heatwave saw a familiar helm break free of the water. "Chase!"

Chase coughed up water, his faceplate barely above the water now. "H-Heatwave! What're you doing down here? Chief Burns gave you explicit instructions not to-"

"Not to leave the Firehouse unless it was a true emergency. I know." Heatwave muttered. He walked over and kicked more debris off of his teammate until Chase was finally able to break free and was washed backward. Heatwave held out his tail, letting Chase hold onto it until the police-bot got his feet underneath him. "Are you hurt?"

Chase leaned forward a little to dump some water out of his open cab. "Just my pride...And perhaps my head." He muttered, putting a hand to his helm. "Leaning forward no longer seems like a wise decision...!"

Heatwave smirked, turning back towards the way he'd come. "Come on, let's get you back to the Firehouse so Blades can take a look at you..." He then paused a moment, sniffing the air. The smell... "...It's you."

"What is me?"

"Nothing, Chase... Nothing at all."