Ashly and the group including their Pokémon are on the way to the ferry having finished their tour of Hokulani Observatory, but however, Ashly's Poipole notices a sign which points to a shortcut to the ferry as Sophocles remembers there is this shortcut leading to the caves, so the heroes venture forth. They soon come to a large glowing cave as Sophocles explains the glowing moss illuminates the area which Mallow sees this is why Sophocles doesn't need a light source. Sophocles states one route even leads to Mount Lanakila which Kiawe realizes this could be troublesome if they don't find the right path, but Sophocles is confident they'll go in the right direction. Kiawe's Marowak who got a bit of the illuminating moss on it's club making it to spins his bone to get it off causing panic among other Pokémon. Kiawe yells Marowak to stop who bumps into Turtonator making the latter falls down on it's back causing a great explosion.

"AAAAHHHH!" The heroes get separated in smaller groups as they are sent away into the depths of the caves as Storm, Poipole, Lycanroc and Kono fall down before Turtonator lands on all four of them and thus, Lycanroc smells the ground to trace others to find them while Sophocles, Lillie and Mallow as well as their Pokémon have landed safely, but don't see others around as Lana, Popplio, Marowak and Rotom after the latter being spit out of Marowak's mouth are in a different section. Marowak panics, but Lana assures they will find others and Rotom promises it'll navigate them in the right direction as Ashly and Kiawe try to search for others. Ashly yells out, but Kiawe asks her to calm down since there are other dangers lurking around and they don't know where they might come from and Ashly accidentally steps on a Boldore who she bows to and apologies to since she didn't noticing the hole making it to accept and leave, but another one showed up.

"AH!" So, she opens her backpack to send Rowlet who is actually asleep and thus, Ashly and Kiawe run off before Boldore goes to explode, but Ashly teleported it to Olivia making her to win against it and has captured it as her own Pokémon. Lillie and others cannot find the rest of their friends, so to determine the exit, Lillie believes they have to use logic. They all raise their hands in the air with their index finger up to feel the breeze of the wind. Just as they feel something, they run away from a rampaging Raticate. After a while, the trio rests and eat some of Mallow's cookies as Lillie notices Mallow hasn't eaten any of them, but Mallow admits she just wished to see the satisfying faces of people that eat her tasty food for her dream is to keep the satisfaction of her customers before she asks Sophocles of his dream who wishes to become an astronaut and uncover the secrets of the universe making him to smile as he got to see outer space, even if it's from a Pokémon's memories.

"It was fun seeing it from Rayquaza's memories really!" Lillie, however, hasn't decided what her dream would be for she likes bonding with Pokémon as the three smile, but hear something going on and they discover a pack of Alolan Sandshrew at training. Suddenly, Togedemaru rolls over to the Sandshrew; Sophocles stops her, but unintentionally gains the attention of the Sandshrew who surround the group. One of them is focused on Mallow's bag and Mallow gives a cookie from the bag which the Sandshrew happily eats. Due to a fork in the road, Rotom calculates the options stating a half chance for either path to take. Without any repercussions, Lana chooses the right path. Ashly and Kiawe are tired as the wonders comments how Ashly could've stepped on Diglett, Boldore and Gumshoos making her to apologies since she can't close her eyes to see with her aura as she'll worry Kiawe making him to sigh as he understands now.

"I want to see Marowak and Turtonator!" Kiawe wishes, but Ashly points out they are at the exit and they rush out, but realize they came to Mount Lanakila. The Alolan Sandshrew befriended Lillie, Mallow and Sophocles as well as their Pokémon as Lillie pets the large Alolan Sandshrew for others have fallen asleep, but suddenly, the Sandshrew become alerted and dash away fast, so the group goes to follow them and as the group goes deeper into the caves, it starts to feel colder. Upon reaching their destination, they see lots of ice in the cave as an Alolan Sandshrew is being hit for a Tyranitar has arrived. The group is alarmed and Lillie notices scratch marks over the pillars and even believes the large "castle of ice" in the middle has been created by the Alolan Sandshrew and a large number of them as Tyranitar overpowers the pack of Alolan Sandshrew with Sandstorm causing Snowy to be swept away by it.

Next, Tyranitar uses Stone Edge causing the ceiling to get cracked as well as injuring the Alolan Sandshrew and the ice boulders fall down separating Lillie, Snowy and Sandshrew from the rest. Elsewhere, Lana and others face another fork in the road as Rotom goes to calculate twenty-five percent chances of the roads, Lana simply chooses the left path to go. Mallow and Sophocles peek through the hole seeing Lillie is okay. Despite the injuries, the large Alolan Sandshrew continues to fight Tyranitar as the Sandshrew evade Tyranitar's Stone Edge, but Mallow and Sophocles fear that will cause the cave to collapse. Thus, Lillie goes to help the Alolan Sandshrew to stop Tyranitar as meanwhile, Sophocles sends Charjabug and goes to dig out through the ice while Sophocles chews the ice, Mallow tries to crash the ice by kicking it as Sandshrew evades Tyranitar's attacks, Snowy uses Hail to replace Sandstorm to help out more.

"This isn't your home, Tyranitar!" Lillie asks for their help to protect the place which the Sandshrew stand up as Lillie points out to Tyranitar this isn't it's home and furthermore, the large Alolan Sandshrew joins Lillie and Snowy in a Double Battle against Tyranitar as Lillie remembering how Olivia had used her two Pokémon Probopass and Lycanroc in sync, Lillie decides to do so now by having offense and defense in balance. Snowy uses Aurora Veil to protect itself and Sandshrew from Tyranitar's Rock Throw and retaliates with Powder Snow as the large Alolan Sandshrew directly follows Lillie's commands hitting Tyranitar with Rapid Spin and as Sandshrew repeats using Rapid Spin, Mallow and Sophocles are impressed by Lillie's tactics. Dodging Tyranitar's Rock Throw, Sandshrew uses Metal Claw topping Tyranitar down and Tyranitar goes to stand up, but Sandshrew utters a cry that scares it away. Mallow and Sophocles come to Lillie being amazed by her recent battle.

"That was awesome!"

"You were amazing out there, Lillie!" Lillie admits she was caught up in the moment, but owes the victory to the Pokémon. The rest of the Alolan Sandshrew return, and start working on the cave. Ashly and Kiawe come out of a cave and encounter Lana and the rest. Kiawe rushes to hug Marowak while Ashly is glad to see Rotom. Out of a different cave, the rest of Ashly and Kiawe's Pokémon appear. Ashly apologizes for the separation since she also had a hard time. Suddenly, Rowlet wakes up, and Ashly bids him good morning making Kiawe comment how carefree Rowlet is. The trio's Pokémon fixes the ice cave and Snowy seals the exit through which Tyranitar escaped with ice as Sophocles sees Charjabug found an Ice Stone which can evolve both Sandshrew and Vulpix and Lillie sees this is the place where the Alolan Sandshrew go to evolve while Mallow notes it is why they wanted to protect the place.

"Hm? Sandshrew?" Lillie asked as she saw the large Alolan Sandshrew touch the Ice Stone with it's nose and evolves into a Sandslash. Everyone is amazed making Mallow believe the Alolan Sandslash is big enough to be a Totem Pokémon. Lillie happily tells the Alolan Sandslash that it could protect it's ice cave including it's pack. Sandslash briefly goes away returning to Lillie with the Icium-Z as a reward which Lillie is touched, but comments she does not have a Z-Ring. Mallow encourages her to take the Z-Crystal anyway as Sophocles believes she could receive a Z-Ring one day as Lillie accepts and makes a victory pose with Snowy. Upon reunited with Ashly and the group, Sophocles tells they had an adventure at the ice castle where Lillie won a battle and got an Icium-Z which Ashly knows and she shows another Rotom Dex that recorded her battle and it was sent to her mother who's face shows up.

"Lillie! Mama is so proud! My little baby girl is all grown up! If Ashly hadn't sent the video, I wouldn't have known! Please keep getting stronger and remember the feelings of your Pokémon when you battle!" She cries happy after watching the video of Lillie winning her first battle as Gladion was there as well, too.

"You've really grown, sis. I never imaging you would be that strong. Keep it up." Lillie blushes as she glares at Ashly for that making everyone to laugh as Ashly isn't even scared. Suddenly, Sophocles notices Charjabug has another Ice Stone and gives it to Lillie as Lillie takes the stone and asks Snowy for it's own opinion. Snowy becomes shy and hides behind Steenee for it does not want to evolve. Still, the group has faith that Snowy will evolve into Ninetales one day and to see Lillie use a Z-Move and promise to cheer for her. Lillie smiles seeing that could be a possibility and Snowy smiles, too before the group departs, Kiawe rides away on Charizard and bids the group farewell as he rest comment Kiawe could've ridden off at any point and see he is just too energetic making Ashly to laugh as Kiawe never stops surprising her really. Once home, Ashly went and started to make a new clothing making both Kukui and Burnet to be confused.

"Done!" Both were shocked as that dress is one they didn't expect at all for Ashly to make (AN: It's the dress from【MMD】Soleil -Haku【4UHD】, but it's not in black/white. It's actually done in colors that don't clash together like aura or Northern Lights color really) making Rotom to take a picture as the wild Rotom Dex is with Lillie as Gladion has one to talk to Lillie with which Rotom has as well, too making it easier to communicate with really making Kukui and Burnet to like this, but still shocked about the dress making Ashly to chuckle as she trills on the spot making it to look perfect to her really as she made a male version for Kiawe with his colors only making him to be shocked as Ashly went all out on it for him as Mimo has a mini version of Ashly's making her to love it very much as it's the same color as Kiawe's making them to have a small dance party on the porch making their parents to smile at the site with a picture taken really.