Between Undella Town and Humilau City, just below the Undella Bay, lies a long tunnel known as the Marine Tube. With its exterior mostly made of see-through glass, one can walk within and observe the underwater sea life, where schools of Luvdiscs, Basculins, Frillishes, Mantines and even Wailords leisurely swim around. However, things are hardly leisurely within the Marine Tube. One by one, the Class E students of the Aspertia Trainer School come around, and wonder just how they ended up at their current location. Cheren hears his name called repeatedly as he slowly regains consciousness, and finds himself surrounded by his students as well as Roxie. He is about to ask where they are when a boy with flaming red hair shows up to greet everyone cheerfully. With an armful of dry twigs, the boy addresses the students as his dear classmates, and believes they must be shivering from the cold. He gets his Gabite to help him piles up the twigs, and orders his Volcarona to set them on fire to keep everyone warm. Yet, despite his hospitality, Mayu, Yuki and Yuuko are hardly impressed. In fact, Yuki grunts with great annoyance, and Cheren feels baffled as the girls seem to know who this mysterious boy is.

Mayu and Yuuko struggle to recall his name, but Yuki hollers that it would be hard to forget the boy since he caused such a scuffle on the first day of school, causing him to get suspended right away. Cheren vaguely remembers that there was indeed someone in Class E who got suspected due to inappropriate behavior, even before he got to meet him, and thinks the student was called Bugger, Bingo or something. The red-haired boy collapses upon hearing the weird names, and quickly clarifies that his name is Benga, student number 6 of the Trainer School's 75th Class E batch. He scoffs that it was no scuffle that he caused back then as he was simply trying to start a properly Pokemon battle, but Yuki strongly begs to differ as she recalls the events of that day. Right after the inauguration ceremony, just as everyone was settling into their classrooms, Benga jumped on stage and pinpointed Hugh, Lack-two and Leo as his opponents without warning. Before the boys could respond, Benga sent forward his Larvesta and Gible to attack, and it eventually led to a forced one versus three battle which not only turned the classroom wet, charred and slimy, but also blew off the windows and tore down the walls.

Benga shrugs that his actions were justified since 'when two trainers' eyes meet, they have to battle'. Yuki fumes that Benga is impossible to reason with, and Cheren decides to intervene and tries his best to pacify the girl. At that moment, someone cries that no fire should be started within the Marine Tube, and sends out a male Jellicent put out all the burning twig piles. A tanned man in swimming wear shows himself, and scolds Benga for putting everyone's life at risk, drawing a sheepish apology from the boy. Cheren quickly recognizes the young man as no other than Marlon, the Gymleader of Humilau City, and walks over to shake hands with him as a polite gesture. Marlon states that it has been two years since they last met, and after spending a moment staring into Cheren's face, comments that whatever possessed him back then seems gone now, causing Cheren to blush.

Benga explains that they are currently inside the Marine Tube, and reveals that he has actually been looked after by Marlon during his period of suspension since he had nothing better to do. Just the day before, he was supposed to resume school, and took a ride on Marlon's boat to return to Aspertia. However, upon arrival, the classroom was empty to his surprise, and he learnt that everyone has gone to Castelia for a choral competition, which led him to quickly follow suit. Just as he and Marlon were about to dock at Castelia, a mysterious sailboat appeared in the sky, and they witnessed the horrible scene of it freezing the entire Castelia City with a powerful cold beam.

Cheren, Roxie and everyone else gasp in disbelief at Benga's words, and the red-haired boy explains how he found them passed out on the harbor and took them for temporary shelter at the Marine Tube. Cheren has a hard time believing what he heard, but Marlon reveals that numerous places across the Unova region have already been frozen by the airborne sailboat. Although it may sound outrageous, it is the undeniable truth, which calls for the necessity to gather up their forces as soon as possible to fight back. The Humilau Gymleader believes that the cold terror is spreading chaos across the region, making it difficult to get in touch with the other Gymleaders. So far, he has only received reply from Iris, who is on the way to join them. Cheren wears a smile as he recalls the incredulous strength of the dragon-wielding girl, and feels thankful to have her on board. Marlon urges Cheren and Roxie to lend their strength as well, which the two readily agree to.

At that moment, Yuki, Mayu and Yuko alert Cheren that Whi-two, Lack-two, Hugh and even Leo are nowhere to be found. Benga finds it intriguing that the three boys whom he beat up on the first day of school are incidentally the missing ones, but Yuki quickly retorts that he was the one who got beaten up. Marlon wonder if they are looking for the girls who took care of them at the harbor, and as soon as he says that, Whi-two, who is actually Zorua in disguise, returns with the two zombie-like Team Plasma girls. No longer in their uniforms, the girls have their Gothoritas handle two boxes of first-aid equipment while they carry warm blankets together with 'Whi-two'.

Cheren hurries over to 'Whi-two' to make sure that she is alright, but the girl simply replies with a smile with a somewhat hollow expression. Marlon states that the girl seems to have lost the ability to speak, much to everyone's astonishment, and Benga wonders if she was too traumatized by what she witnessed at Castelia. Yuki, Mayu and Yuuko begin to gossip among themselves, and recall what Hugh said there being a Team Plasma member among the girls in their class. They steal a glance at Whi-two, who has been quite the prime suspect so far, but find it unconvincing since it wouldn't be logical for her to stay behind if she really is a Plasma member. Moreover, an evil organization would not be helping the need like she is. Yuki, Mayu and Yuuko decide to disregard Hugh's assumptions, and walk over to show their encouragement to 'Whi-two' by offering to help her out. While the other Class E students are tended to, Marlon discusses what to do next with Cheren and Roxie. Marlon reveals that in addition to Castelia, Nacrene and Striaton have also been frozen, and the sailboat is edging closer and closer to Undella Town. He is calling for an evacuation of the Undella and Humilau residents to the Marine Tube, and thinks they shall begin their retaliation afterwards. Cheren, on the other hand, wishes to ensure the safety of Lack-two, Hugh and Leo first, since it is his responsibility as a teacher to look after his students. Marlon thinks it is a fair point, and proposes to establish an effective means of communication in order to gather or find people, which Cheren fully agrees.

Meanwhile, at Aspertia City, Looker and his Croagunk venture into the urban area's narrow streets, and make their way to the Game Arcade where Lack-two has taken them before. Once inside, Looker reaches for a coin to activate the secret opening at the jukebox. However, before he could do so, the trapdoor opens on its own, and the Magician barges out with a huge baggage on his back. With his Corphish sitting on it, it appears as if the chubby man has packed all his belongings and plans to be away. Looker quickly asks if Lack-two has come by, and the Magician nonchalantly replies that he hasn't. Looker starts to wonder, though improbable, if the boy could have fallen victim to the mysterious frigate's attacks since he has not been able to get in touch with him since the day before, but the Magician seems to show no concern. Instead, he wants Looker to move aside, and states that whatever happens to Lack-two has nothing to do with him now. His statement astonishes Looker, since he is supposed to be the young superintendent's personal assistant of some sort. However, the Magician reveals that it is in the past now, since Lack-two has been fired by the International Police and is no longer a superintendent.

The shocking revelation hits Looker like a radical, and the man exclaims that he has not been informed of it at all. He finds it hard to believe that the Magician has news not even officers of International Police force are aware of, and the Magician cryptically states that there are only so many ways that people in the underground network like him gets access to insider information. The word 'underground' immediately captures Looker, and he realizes with a start that the Magician must have hacked into the International Police's computer system.

The Magician states that he works as a spy, or to word it better, source of information, for Lack-two. In addition to collecting and supplying information, he also manages Lack-two's physical status and maintains his artillery. However, what he does is technically illegal. In return, Lack-two gives him monetary rewards, and also discloses to him the security loopholes that allow him to freely navigate within the International Police's computer system.

Looker's eyes widen with bewilderment upon hearing the Magician's revelation, but the chubby man is hardly bothered about telling him the truth. He recalls how Lack-two's physical monitors went down for no reason the evening before, prompting him to access the International Police's computer system to find out what might be happening. To his surprise, there was a report that Lack-two has committed a severe misconduct by retrieving without permission a highly dangerous Pokemon under the International Police's surveillance. Looker instantly knows that it must be Genesect, as he has seen the boy using it at the Castelia Sewers. The Magician reveals that Lack-two has in fact done something far more risky, and reminds Looker how the cassette-like items known as Drives can change the type of Genesect's Techno Blast. When the Pokemon was captured, it was equipped with the electric-type Shock Drive, and Lack-two has requested him to use to as a prototype and recreate the fire, water and ice type versions. Alas, he has failed the task embarrassingly, only managing to finish an imperfect fire-type Drive. Nevertheless, Lack-two snatched it away from him the day before, despite his warning that using it may lead to an explosion.

As the information sinks in, Looker rationalizes that Lack-two's actions must have somehow reached the ears of the superiors. The Magician confirms it to be the case, and says it has thus led to the boy's discharge from the police force that morning. The chubby man adds that his secret lab has also been uncovered by the International Police, which is why he is skipping town, even though it is during bright daylight. Before bidding Looker farewell, the Magician informs him that he lost contact with Lack-two somewhere near Castelia's waters, and that the boy's three Pokemon, Dewott, Kabutops and Gliscor have all been knocked out at the construction site of the PWT.

Far out at the PWT's construction site, Lack-two's three Pokemon indeed lay motionless on the ground as the Shadow Triad tower over them with the legendary Tornadus, Thundurus and Landorus in Therian Formes. The three men are slightly annoyed how pesky their opponents have been, but agree that they live up to their names as Pokemon trained by the International Police. Knowing that the Plasma Frigate is about to arrive at Undella Town, the Shadow Triad decide to head to Humilau, where they would catch up and get back on board. Without another word, they vanish along with the legendary Therians, leaving Lack-two's fainted Pokemon behind.

At Striaton, the whole city is covered in frost, and residents struggle within their homes to keep warm. At Fennel's Lab, Aria Juniper cringes with horror as she learns from the radio that following Castelia, Nacrene, Striaton, Mistralton and Opelucid, Lentimas Town has also been frozen over by the flying sailboat. Her father, Cedric Juniper, finishes up his call with Drayden, and relays the Opelucid mayor's suspicion that the powerful ice-type energy likely originates from Kyurem, which means the frost dragon has already fallen into the hands of Team Plasma, and that the flying sailboat is under their command. Aria wonders if the other Gymleaders have responded, and Cedric reveals that they are not receiving any reply from Cheren, Virbank's Roxie and Humilau's Marlon on the Gymleader's hotline. Hearing that, Bianca breaks into tears, and Aria quickly tries to comfort her. Bianca states that she has been trying to contact Cheren via the Xtransceiver repeatedly but to no avail, and fears that she will be losing Cheren like how she lost Black.

At that moment, Amanita barges in to get everyone's attention, and in her Cubchoo costume, wants them to come with her as their lab owner, Dr. Fennel, has finally done it. Feeling baffled, Aria, Cedric and Bianca follow Amanita to find Fennel standing in front of her complex machineries, and the young woman cryptically states that 2 years has been a very long period. Ever since she got her hands on the Dream Mist, Fennel says she has worked day and night to search for the realm that can be called an alternate dimension since it may or may not exist. Aria tries to say it is not the time for such a topic, but Fennel shuts her up and wants to know if she remembers who Prof. Burnet is. Aria recalls that she is a university friend of Fennel's who likes pro-wrestling, and Fennel reveals that working with Burnet has allowed her to achieve major breakthrough in her research. Now, it is time to verify an assumption she made about the alternate dimension known as the Pokemon Dream World. 2 years ago, when Reshiram reverted into the Light Stone, Black was caught up in the collapsing energy field. In her assumption, the interior of the Light Stone is actually connected to the Pokemon Dream World, which is where Black currently exists.

Upon hearing Fennel's words, Bianca goes berserk, and runs over to grab the young woman by her collar, demanding to know where the Pokemon Dream World is, whether it is in some town, city, route or mountain. Fennel replies that the Pokemon Dream World is believed to connect with the real world at a place known as the Entralink, which central spot is concentrated with dream energy. Bianca immediately decides to head off to the Entralink, but Fennel stops her, and reveals that she has already sent someone to verify the fact. Just as Bianca demands to know who it is, a voice speaks through Fennel's Xtransceiver, and addresses both Bianca and Fennel.

It turns out that the person whom Fennel bestowed the task upon is no other than White, who is currently standing in the center of the Entralink, accompanied by Amanda, her Serperior, and Solly, who has now evolved into a Duosion. Ahead of her, the Light Stone lies in the middle of tree sprout behind a blue hexagonal ornament. White informs Fennel of her discovery, and crouches down to pick up the shimmering white object. Gently cradling it in her arms, she wears a smile and feels grateful that she has finally found Black.

At that moment, the silhouette of a black dragon hovers past her, kicking up a swirl of wind as someone disembarks. White looks up from her kneeling position, and finds herself face to face with N, the former King of Team Plasma…