This story takes place during the events of Ice Age 3, commencing directly after Rudy was defeated by Momma Dino. Sid is feeling lonely without his family, and although he was saved by Buck and the herd from the dinosaur world, he still had those thoughts. After seeing Peaches being born, he felt more lonely than ever. So when the time comes to leave the dinosaur world, Sid decides to stay with Momma Dino and the kids instead.
"He's gone...what am I supposed to do now?" Buck said, staring down at the abyss that Rudy had fell in from Momma Dino's strength just now, as his voice was less-hyperactive and more regular.
"That's easy..." Ellie claimed, walking besides Manny as the herd stood together in the midst of the tropical weather, "come with us..."
Buck raised an eyebrow from his only eye, surprised at the offer.
"Y-You mean...up there?" he diverted his eyes to the ice surface above the underground tropical world, as the heat from the conditions here made it feel as if sweat was coming out from their insides.
He slowly walked back towards the edge, holding onto his teeth trophy from Rudy, as it dawned on him that he hadn't been back 'up there' in forever. It was surreal for him to remember that this dinosaur land was underground. He's lived here for that long, it indeed felt as if this world was the real thing. The sound of chirpings from the tropical dinosaur birds amongst the trees on the lower part of this area hadn't distracted the herd, nor Buck. It was like they were in an oven, the tropical heat was that much.
"I never thought of going back..." Buck said, walking further along the rock to stand near the surface that led to the lower ground of the dinosaur world, "I've been down here for so long it..feels like up to me. I'm not sure I can fit in up there anymore..."
Buck simply stared at the ice roof, held on by those gigantic ice-like pillars that kept the dinosaur world in place by stopping the ice from collapsing. His mouth opened as he had an expression that seemed to be like a mixture of uncertainty and shock at the prospect of going back up.
"So...look at us?" Diego said, with a cheerful expression, "do we look like a normal herd to you?"
Sid, however, wasn't looking normal in the slightest. Whilst everyone had stood in place, smiling, trying to give the impression to Buck that they truly are normal, in order to convince the weasel to come back up to the surface, Sid turned his green head to the direction of the sun, specifically, the path that Momma Dino and her three dinosaur babies had left in just now. He felt...lost, suddenly. His lips were dropped, and his heart had an everlasting ache, as if he was missing somebody. Manny, though, slapped Sid gently, connecting fur to fur with his trunk, to get Sid back into the game. The sloth joined in with the herd to smile at Buck, but that didn't hide the corners of his lips shaking and vibrating as he was trying to conceal his hidden sadness.
As Buck couldn't hide his smile at the herd, he confirmed his departure from this tropical paradise internally. He walked up to the herd, carrying his well-earned trophy in the form of Rudy's tooth, looking for the cave entrance that led the way up to the surface above. Sid, however, was reluctant in fully following the herd. As they all led the way for Buck, the sloth remained in the clear view of the tropical sun, as he kept switching his head back to the direction of those gigantic tropical leaves in the most natural-looking green.
His eyes caught on those two gigantic pillars, as it dawned on the sloth that Momma Dino was most likely already far gone. He placed his hand onto his green messy chest, before raising his other hand out, as if he was holding the hand of somebody in front of him, feeling like he was, once again, abandoned by his family. Sure, Momma Dino was just that; a dinosaur, and a Tyrannosaurus Rex, alongside her kids, but Sid's family spirit for them was truly stuck into place when she had gave the sloth a sleeping place in that space within the rocks last night as if he was one of her kids, just as Rudy passed by. The sloth truly felt like he was a tiny fish in a gigantic pond, now that he's without the dinosaurs that he stuck with during the majority of his time in this underground tropical place.
"SID?! YOU COMING?!" Manny yelled, noticing that Sid was still standing where they were just now.
"SORRY! I'M ON MY WAY!" Sid replied, running off like the clappers back towards the herd, albeit feeling reluctant and hopeless without Momma Dino and her kids.
As Peaches held her trunk around her mother's tail, with Manny keeping her stable from behind to make sure that she didn't fall off the skeleton dinosaur bridge, Buck was right behind the herd, but Sid was even further behind. He just couldn't make himself fully go through the cave back to the surface; the bottom line was, he wanted to be with Momma Dino. As Buck got as close to the surface as he's ever been in ages, he stopped at the top of the skeleton dinosaur, and looked like he was contemplating for a moment, rubbing his tooth trophy.
"So long, big guy..." the weasel proudly said, gently sticking Rudy's tooth into the head of the skeleton dinosaur, before continuing his way up.
The herd hadn't noticed that Sid wasn't here; they were all too caught up with Peaches, and it was the same with Buck. He didn't bat an eye at anything, he was that nervous about going back to the surface. Suddenly, though, just as he walked, the entire vicinity of the cave vibrated as that ever-fearsome roar of Rudy's had been emitted from back down below, sending an echo throughout the cave.
The herd stopped, before they increased their speed significantly after hearing the roar, but Diego remained behind; he knew Buck had another plan up his fur.
"That's our cue, come on Peaches..." Manny said, encouraging Peaches to move gently with his trunk.
Sid was just at the bottom of the skeleton dinosaur, which meant he was still on the side that would safely take him back into the sunny, tropical atmosphere of the dinosaur world. The sloth heard the roar, and although it sent a shiver down his spine, he still wanted to stay here; what he isn't aware of is that shortly, Buck was about to return, due to hearing a confirmation that Rudy's still alive. The sloth simply ducked down as he waited for the right time to go back in.
"He's alive..." Buck semi-whispered, looking back into the direction of the skeleton dinosaur with a smile, before being confronted by a concerned-looking Diego.
"B-Buck?" the sabre-toothed tiger asked.
Buck turned around, looking at Diego as if he's changed his mind. His weasel face was straight, but he also had a mixture of confusion, as he let off a very brief puff.
"I..." he moved both his arms to the direction leading back down the bridge, "I've gotta..." he couldn't say his entire sentence because of the fear of disappointing the herd.
Diego understood Buck's desire easily; he knew the weasel was tough enough to tackle those dinosaurs by himself, so who's stopping him? Diego smiled at Buck, as the sabre-toothed tiger seemed to be neutral with Buck's decision.
"Yeah..." Diego nodded, realizing what the weasel wanted to do.
"B-Besides...this world should really stay down here...take care of em, tiger..."
"Always listen to Buck..." Diego said, smiling one final time at Buck as he turned his body around slightly, before fully jumping his tiger paws over the obstacles and bumpy rocks of the cave.
Buck nodded at Diego's evacuating body, appreciating him for accepting his desire. He genuinely saw Diego as a good friend, so that only gave him a bigger reason to smile at him like a close pal as he was leaving. The weasel ducked down, took a hold of Rudy's tooth, and stared at it briefly.
"Hmm..." he emitted, coming up with a fun, agility-style fashion of returning to the dinosaur world, before re-doing what he started ages ago with Rudy.
He grabbed ahold of one of the ropes holding the skeleton dinosaur in place, before snapping it in half, elevating his small weightless body into the air, as the entirety of the structure started collapsing as a result. Sid began hearing the thunderous falls of the rocks, and he noticed, in the midst of the gigantic clouds of dust emerging due to how many rocks were falling, that the skeleton bridge had fell down; that shocked him in particular, but there was no time to react. The sloth ran for his life, as Buck had already beaten him back to the entrance into the dinosaur world as he chanted for Rudy in an extended fashion, before cheering energetically as he swung.
Sid leaped for his life from the cave, just barely avoiding the collapsing rocks, as it dawned on him that all of that time spent just now, saving him from this world, was wasted and useless; Sid was once again stranded in the dinosaur world, but the sloth had a good purpose for it. As he stood up from his green body on the warm, flat surface of the upper edge near the entrance to this tropical world, Sid had caught onto a small, yet very flexible body just swinging amongst the vines, dangling down from the tropical trees.
"BUCK?!" Sid yelled, as his voice had echoed well into the distance of the dinosaur world, but it still wasn't enough for the weasel to hear him.
"Oh no...how will I ever get back out now..." Sid asked, realizing that the entrance was now blocked off by one of the gigantic rocks that had fell just now, as a result of Buck's snapping of the ropes.
But the sloth also remembered why he came back here; he wanted to stay with Momma Dino, and if there's any high chance of survival in this world, then it's being with the dinosaur who you had established a good bond with. Sid, as a result, wasted no time in sprinting his way down towards the descending surface leading to the bottom ground of the dinosaur world, and he recognised the positioning of those tropical trees and the giant ice pillars. The sun was in his eyes, blocking his vision, but all he cared about was being able to run in a manner where he could quickly find Momma Dino and confess to her how he's felt; he wants to be apart of her family, and he couldn't express it enough to her how grateful he is for her showing her soft side to him. If he finds her again now, he'll be able to show his gratitude, whilst also admitting that he's had a connection to her as if he was truly one of her kids.
"W-Where's Buck?" one of the possums asked, as Diego was breathing heavily from having to sprint out of the collapsing structure of the cave just now.
Diego let off a peaceful smile, briefly looking back at the cave entrance itself, which was now blocked off.
"Don't worry, he's where he-"
"Uh, please tell me Sid came back with us?" Manny asked, realizing that Sid wasn't here.
"Oh, uh..." Diego said, gulping as the herd looked back at the cave.
"M-Manny...w-..."
The herd was speechless; Sid was truly back down there, and what's even worse is that now, the entrance was blocked off; they couldn't find a way of saving Sid in the slightest. All of that time, spent...and Sid goes back down to that tropical paradise.
"M-Manny, I think we need a compromise, and FAST..." Ellie said, standing with Peaches.
They were genuinely lost with words. How they were going to go back down there, if they can that is, was a clueless thing for them. They found it impossible, as well. They cared for Sid, even though they mostly found it hard to show it, evident by their reactions just now to the sloth going back down into the dinosaur world.