At the Driftveil Gym, Black gasps in shock when Clay reveals that the excavated artifact, Dark Stone, is the legendary black dragon Zekrom itself. He requests to know how it happened, but Clay confesses that he has no idea either. The only thing he learnt from Lenora is that, Zekrom turned into a stone on its own will, but none of the literature documented the real reason.

The Driftveil Gymleader states that usually, he only focuses his mind on his business, and doesn't give a damn about legends and myths. However, the situation is different this time, and he must pay heed because his mining business might be at stake. In fact, the Pokemon League which Black is aspiring to conquer may also be cancelled, and Black jumps in horror upon hearing the news. He frantically asks Clay why it is, but Clay says he has already spoken too much, and if Black really wants to know, he must beat him in a Pokemon battle first.

Black remarks that he has no objection to that, and retrieves Costa to send out Musha. Clay calls back Excadrill as well, and gets Palpitoad back onto the field. Palpitoad lashes out its long tongue to attack, and Black tells Musha to evade. However, the blue toad manages to catch Musha, and wraps its tongue around its pink body.

Clay laughs that it is not easy to escape from Palpitoad's long and sticky tongue, and Black states that he will not try to escape in that case. He orders Musha to turn back, and ram hard into Palpitoad, who is unable to dodge since its tongue is wrapped around Musha. Clay watches as Palpitoad faints from the powerful attack, and recognizes the move as Zen Headbutt. He compliments Black for turning the restraint to his own advantage, but tells him not to be too happy as of yet. As soon as he says that, Musha faints onto the ground, and Black jumps in surprise. Clay explains that Palpitoad's tongue wrap also inflicts damage on top of restricting its foe's movements, and Black grunts that they had a double knock-out.

Clay then sends out Excadrill again, and Black decides to choose Nite. The Driftveil Gymleader states that for the sake of victory, he is ready for some sacrifices, and tells Excadrill that it has his permission to drill however it wants on the battlefield. The subterrene Pokemon immediately folds itself into a driller, and digs a hole to vanish underground. Black warns Nite to stay cautious, but Excadrill exits right beneath Nite, and slams it up into the air. Before Nite could retaliate, Excadrill disappears underground once more, and the same process goes on several times.

Black grunts that he has to find a way out, and at that moment notices that the entire field has been covered with holes. He asks Clay if it is alright that so much damage to done to the arena, but the man grins that he has the repair fee all covered. Black feels glad to hear that, and remarks that he will have no concerns in that case. With that, he motions to Nite, and orders it to deliver repeated strikes at random spots on the ground. Since he could not predict Excadrill's movements, he will make holes as a counter attack.

And so, Nite continues to slam through holes on the ground, and occasionally lands a blow on Excadrill who is incidentally at the spot. The continuous drilling and slamming cause rocks and boulders to fly everywhere, and some eventually smash against the power supply, exploding it. The entire room falls into darkness instantly, and Clay notes that not only the lights are out but the conveyor belts have also stopped.

Just then, Black hears a crash, and wonders if everything is alright with Nite. He uses his Pokedex as a flashlight, and discovers with surprise that both Nite and Excadrill have fainted. Clay states that they had a double knock-out again, and sends out his final Pokemon, Krokorok, while Black calls forward Costa.

Clay points out that although Krokorok received damage from Tirtouga at the beginning, it still manages to stand, and gets it ready to attack. Black sees that he has the type advantage, but to be honest, Costa is too unpredictable and he doesn't know its true strengths either. By accident, he must now fight in the dark, which he did not expect, but he rationalizes that the situation must be the same for Clay. Recalling how Costa's water attack inflicted considerable damage on Krokorok, he hopes that the odds are on his side.

Suddenly, without warning, Krokorok charges forward, and delivers a bite on Costa. Black couldn't see what is going on, but is shocked that Costa has been hit. He fails to understand how Krokorok managed to land a blow, and starts to wonder if it is able to see in the dark. Clay laughs at Black's query, and confirms that he is correct. He reveals that Krokorok's eyes are covered by a special membrane, which can sense the heat of objects and allows it to see even in total darkness. Indeed, the desert croc detects Costa's whereabouts with its infrared-like vision, and dives forward to deliver another bite, which lands right on the Tirtouga's fore-fin.

Clay believes Black must think that he has the upperhand since Krokorok previously received damage, and points out that Black not only has the type advantage but also has the better defense. However, his Tirtouga is still not in sync with him, and his Krokorok can see it while the reverse isn't true, which together put him at an equal disadvantage. The Driftveil Gymleaders grins that they are both having a 50-50 chance of winning, and Black thinks hard to come out with a strategy.

Black tells Costa to curl itself up into a protective state, but Krokorok soon spots it again. Clay states that even though Tirtouga folds itself up, it will still give off body heat and cannot evade Krokorok's vision. He tells Black to get ready for the final blow, and orders Krokorok forward. However, as the desert croc charges forward, its infrared vision detects two identical looking objects, and gets confused as to which is its foe. He randomly takes a guess, but upon munching down, discovers that it is Black who has curled up with a piece of rock to imitate his Tirtouga. Black winces in pain from the bite, and shouts for Costa to unleash a water jet towards the direction of his voice. Uncertain of what is going on, if does as it is told, and blasts out a powerful stream of water which hits Krokorok and faints it.

Black grins that he has won, and tells Clay to carry on with his story. Both Costa and Clay are astonished by what Black just did, and the man is still having a hard time believing that the boy used his own body as a bait to trick Krokorok. He breaks into a laugh, and says Black is certainly an interesting lad.

Black's Tula then uses Flash to temporarily light up the area, and Blacks sees that Clay's Pokemon have gathered around Costa, appearing as if they are idolizing it. He wonders what they are doing, and Clay says although he doesn't understand Pokemon language, the scene looks like a group of young ones asking for stories from an old man. He remarks that the Tirtouga is clearly even older than he is, and jokes that Black should perhaps nickname it Old Mr. Costa.

The Driftveil Gymleader then points out that all the elevators have stopped working, making it impossible to come in or go out, which creates the perfect opportunity for them to talk, without worrying about being spied on. Black jumps in surprise upon hearing the word 'spy', and Clay explains that ever since the Dark Stone has been excavated, hidden cameras have been set around them to watch their every move. Black wonders if it could be Team Plasma, and Clay replies with a nod. However, he states that it is about the only thing they know now, and they postulate that the organization's target is the Dark Stone, a fact which causes Black to bolt in shock.

Clay remarks that they have no idea how the Dark Stone will transform back into Zekrom, and what will happen if it does. Yet, according to Lenora, only disastrous things can follow if what happened in the legend of the founding of Unova is brought to reality, which is why all the Gymleaders have decided to gather and prevent this from happening. Of course, their enemies are not fools, and would certainly not show up if all the Gymleaders gathered at one place. In order to lure them out, they have kept that Dark Stone at the Museum, where Team Plasma has their eyes on, while assembling the Gymleaders somewhere else. Then, once they are ready, Lenora will pretend to lower their security at the Museum, which will surely be picked up by the spy cameras, and give the enemy the false impression that it is the perfect time to act. When the enemy does come, they will have the chance to bring down the organization all at once.

Clay hopes that Black will be glad to know that he has been invited to join their battle, and says they must head off to the assembly place now. Black wonders how they could get out of the Gym when all the elevators and conveyor belts have stopped working, but Clay tells him not to fret. The man walks over to the emergency switch to turn everything back on, and Black instantly collapses, realizing that there is backup electricity after all.

And so, following Clay's lead, Black leaves Driftveil City, makes it past Route 6 where a Season Research Lab is, and works his way through the Chargestone Cave. Upon exiting the cave, Black pants to catch his breath, and wonders if they have arrived yet. Clay jokes that he needs to build up better physical tolerance, but tells him the good news that they have arrived. The Driftveil Gymleader points ahead to the city of Mistralton, which houses an airport with runways, and gestures towards a white building in the north, which is the Celestial Tower, the Gymleaders' assembly place…