Now this is the type of battles I want to see in my Gym battles, not the clowning around that happened in the Nimbasa Gym! With a bag of Revival Herbs, Ash & co. have come back to the Gym and are allowed in this time. They find Clay and give him the Revival Herbs and, as they agreed, Clay leads Ash & co. to the Driftveil Gym's battlefield to battle Ash. Clay starts things off with his Krokorok and Pikachu is charged up for battle, however Ash stops it as Krokorok is a Ground-type and Ash starts thinking what Pokemon he should send out to start their Gym Battle. What Pokemon will Ash send out first? And afterwards what would Clay's and Ash's other Pokemon be? Will Ash let Pikachu battle or will it be (rightfully) sitting on the sidelines for this battle? Will Ash start out thinking smart or did he replace one of his Pokeballs with an Idiot Ball? One way to find out, DIG in *gets hit with a brick*:

Digging Right Into Battle:
We start the episode with Ash & co. coming back to the Driftveil Gym where the door opens and one of the Gym's worker comes out asking what they want. Ash tells him they have the Revival Herbs that Clay have asked for so that they can battle and the worker leads them to an elevator which goes down. In the elevator the worker asks if Pikachu will be battling (knowing Ash, probably) and Ash says it'll depend on what Pokemon Clay uses (so I guess that means Ash has all his Pokemon with him this time...). The worker said a "cute" Pokemon like Pikachu can't stand against Clay's Pokemon which are "extremely powerful" and starts laughing though Ash just gives a sly-looking smile (don't mistake that for Ash having a plan, he just knows the plot will let Pikachu break the rules if need be). Finally arriving down below in the mines, Ash & co. run out and find Clay who greets them and asks if they got the Revival Herbs which Ash says they did and gives Clay the bag who's impressed and gives it to a worker to give to the Pokemon who need it (something happened down here in the mines?). Ash asks about having their Gym Battle and Clay says of course as he keeps his promised and they walk over to a door which Clay did a fancy pickaxe swing before pressing a small button which opens the door (yes, I see the pickaxe swing was important in order to push a button ). The doors slide open revealing the battlefield and Ash and Clay walk over to their sides as the worker announces the rules (3-vs.3 single battle, Ash may only substitute) while Iris and Cilan are impressed that the gym is this far underground.

The battle starts and Clay sends out Krokorok as his first Pokemon and Pikachu is ready to battle but Ash isn't sure:

Ash: Hold on Pikachu, we got a problem. Krokorok is a Ground-type, your Electric-type moves won't be effective against it.
Comment: That hasn't stopped you before sending Pikachu out against a Krokorok, unless having sunglasses somehow changes a Pokemon's type.

Ash's first Pokemon is instead Oshawott and starts off with an Aqua Jet however Krokorok uses Dig last minaute to dodge causing Oshawott to slam against the wall, knocking it back. Krokorok uses Sandstorm hitting Oshawott multiple times but, worse yet, it got sand in Oshawott's eye making it unable to see. Krokorok uses Bite which hits and Oshawott tries using a Razor Shell however Sandstorm activates and gets sand in Oshawott's eyes, blinding it and it starts swinging around its Razor Shell in a panic missing Krokorok. Krokorok uses Stone Edge which hits and knocks Oshawott back but Oshawott gets back up only for Sandstorm to blind it once more but getting hit with the Sandstorm himself gives Ash an idea. Ash tells Oshawott to aim at the field and use Water Gun and Oshawott does so by spinning around which creates a pillar of water to rise up and cause it to rain which washes away the Sandstorm. Krokorok uses Dig but Oshawott start filling the hole up with Water Gun pushing Krokorok out of another hole and hits it with an Aqua Jet and Razor Shell, knocking out Krokorok which gets Clay mad while Oshawott high fives Ash and Pikachu though Cilan reminds us the battle ain't over.

Clay returns Krokorok and says Ash may be a "whippersnapper" but he has spirit and sends out his second Pokemon: Palpitoad. Iris notes Clay's Palpitoad looks stronger then Ash's (forshadowing a shadow match?) and Cilan says it's Water-type half will complicate things. Ash asks Oshawott if it can keep going which it can and so it does Water Gun and Palpitoad counters with Hydro Pump which beats Water Gun and slams Oshawott against the wall. Oshawott uses Razor Shell but Palpitoad counters with Sludge Bomb and knocks Oshawott's Scalchop out of its hand which Ash tells Oshawott it's behind it. Palpitoad uses Rock Smash during this moment of panic and hit just as Oshawott picks up its Scalchop, slamming it into the ground and knocking it out.

Ash returns Oshawott as Clay says he's not too sure about his previous thoughts on Ash though Ash says it's a one-on-one match so they'll see what happens. Clay asks for Ash's second Pokemon which Ash thinks about a type that's strong against both and realizing a Water/Ground-type is only weak to Grass-types, chooses Snivy as his 2nd Pokemon. As always, Snivy starts off with an Attract surprising Clay.

Iris: Huh? Attract? Why would Ash use a move like that?
Comment: ... really? Have you not seen Ash's other battles where an infatuated Pokemon is essentially a sitting duck? Do you not remember how much trouble your Emolga's or Bianca's Minccino's Attract move is?
Cilan: Why? Because it's a typical Ash move, that's why.
Comment: Cheap and annoying, perfectly describes Ash.

Unfortunately for Clay, unlike Elesa's Emolga, his Palpitoad is male so it becomes infatuated with Snivy and takes Vine Whips (*insert BDSM joke here*) and a Leaf Blade (and loving it...). One Leaf Storm later, Palpitoad learns that love hurts and is knocked out getting Clay even angrier as he stomps the floor and returns Palpitoad.

Forcing A Build Up:
Clay says he's getting mad and if there's one thing he can't stand for is an unfair battle (geez, he sounds like a 2-year old who just lost in a board game).

Ash: Unfair, what are you talking about? That was just my strategy.
Comment: As I said, cheap and annoying.
Clay: STRATEGY? A young whippersnapper like you should forget about strategy and attack head on.
Comment: How do you know how Ash usually battles?
Clay: Like a man!
Comment: I AM A MAN! *punches off screen*

Clay says he'll have to use his secret weapon, a Pokemon who's power is on a level beyond the rest of his Pokemon and sends out his third and final Pokemon: Excadrill (hmm, interesting, Clay so far is the only Unova Gym Leader to not have used a Pokemon we haven't seen yet). Excadrill gives out a roar as Cilan reminds us it's Ground/Steel-type and Snivy uses a Vine Whip but Excadrill counters with a Rapid Spin (where it just spins its shovel claws) which knocks away the Vine Whips. Snivy uses Leaf Blade but that too is knocked away by Rapid Spin so next up is Attract but even the power of love can't get through spinning rapidly (though this time at least Excadrill did spin itself instead of just its claws). Snivy tries its last attack Leaf Storm however Excadrill goes back to claw spinning Rapid Spin and mows through the leaves like a weed whacker and knocks Snivy back. With nothing else for Snivy to do, it's time for Excadrill to end this battle and uses Horn Drill which knocks Snivy out.

Ash returns Snivy and says his goal is to become a Pokemon Master and he's not about to give up which Clay responds by picking up his pickaxe and tells Ash to look at it. Clay says he began digging this mine with that pickaxe and his Excadrill when he was about Ash's age (that can't be, Ash is immortally 10 and your obviously older then that) and yet Ash wants to become a Pokemon Master "lickity split" (when did Ash say that?).

Clay: I used this pickaxe to dig every square inch of this mine which earned me the title "King of the Mine".
Comment: I thought your Leader Title was "Underground Boss"?
Clay: So my job is to show you just how tough the road to the top really is you see.
Comment: Uh huh, Ash has been in 4 Leagues, taken down several Legendaries, and won the Gen III Battle Frontier (even being offered to be a Frontier Brain himself), I think it's safe to say Ash already knows it's tough to get to the top and even if he didn't it's going to take a greater force than you to do it.

Suddenly Ash has his eyes covered with his hat and his fist clenched:

Ash: Listen, when I tell you I'm going to become a Pokemon Master, I know what I mean. AND I'LL PROVE IT WITH MY LAST POKEMON!
Comment: s*** just got real, yo.

Clay says "talk is cheap" and so Ash should "walk the walk" (because "he who hesitates is lost" and "your bark is worst than your bite") as Ash decides he needs a Pokemon to hang in there and than can dish out damage so decides his third and final Pokemon should be... Roggenrola! Clay chuckles as Iris points out that Roggenrola is weak to both Ground and Steel-types (not to mention Ash had other better options like Swadloon and Scraggy, even Tepig's Fire-type attacks would do super effective damage) but Cilan says Ash might be depending on Roggenrola's toughness (yeah, but Excadrill has a crazy high Attack stat and its STAB moves are super effective on Roggenrola, I think that evens things out in Excadrill's favor). Roggenrola starts with a Sandstorm (I don't think this is irony, but close to it) and Excadrill uses Drill Run going underground and coming right from under Roggenrola tossing it up into the air and keeps it up tossing Roggenrola all over the place. Clay gives Roggenrola credit for surviving this long and Excradill does a Horn Drill hitting Roggenrola straight on (now Roggenrola has Sturdy which should only be active if it's at full HP however I'm sure the anime changed it because of plot). After Excadrill is done using Horn Drill, Roggenrola is still standing but is doing nothing as everyone watches it, however it soon starts to glowing in a very familiar way... ROGGENROLA IS EVOLVING!

Rocking The Mine:
After an impressive evolution sequence with glowing red eyes of DOOM, Roggenrola evolves into a Boldore! Excadrill starts with a Horn Drill but Boldore still has the Sturdy Ability so it does nothing except force both Pokemon back. Excadrill uses Drill Run but Boldore grabs Excadrill and forces it out into a grapple which gets Clay giddy to be fighting a "whole new challenger". However the oranges crystals on Boldore's head start to glow and Boldore uses on of its new moves, Rock Blast, which forces Excadrill to its knees (despite it being quad resistant to Rock-type attacks...). The orange crystals on Boldore's head are still glowing though and so it does a Rock Smash which Excadrill counters with its own Rock Smash and they both collide but Excadrill's injuries get to it and Boldore scores a hit knocking Excadrill out, winning Ash the badge!

Ash runs up to Boldore congratulating it as Boldore jumps on and starts crushing Ash. Up on the surface evening has come and everyone is outside as Clay congratulates and thanks Ash telling him that he (Clay) worked hard to building the mine and becoming the face of Driftveil City and wants Ash to remember how hard he (Ash) worked in their underground battle while training to become a Pokemon Master. Clay then gives Ash the Quake Badge and Ash does his victory pose with his Pokemon.

Back at the Pokemon Center that night, Cilan and Iris talk about it being a tough battle and Ash says his Pokemon gave it their all as the healing ring goes off and Nurse Joy comes out with Ash's Pokemon saying they're okay. Nurse Joy asks where they're going now and Ash says he'll be heading to the next Gym so Nurse Joy points them to the direction of Mistralton City (because someone had to) which Ash decides that's where they'll go next ending the episode.