[ Rats squeaking ] How can you be sure it's even real, grandpa? I always thought it was just a story if you read between the lines, Robert Louis Stevenson's clues were unmistakable and lead right to ahh! Stay behind me, Kai. Whoa! This can't actually be - Dr. Jekyll's secret laboratory and - His legendary formula. Sir Morton: Which belongs to us. Forever King: The royal order of Forever Knights thanks you for your assistance in recovering our formula. Your formula? Forever King: The good Dr. Jekyll was one of our order, crafting alien blood into a superstrength serum for our knights' use in battle. We shall take it and be on our way. Aah! [ Grunts ] [ Screeches ] Kai, run! [ Grunts ] [ Grunts ] [ Grunts ] Forever King: One vial is more than enough for my uh [clears throat] Our purposes. Bring the old man to the castle. We shall require his expertise to recover the sword. [ Grunts ] [ Cellphone beeps ] [ Ringing ] Ben 10 he's a kid, and he wants to have fun but when you need a superhero, he gets the job done Ben 10 with a device that he wears on his arm he can change his shape and save the world from harm when trouble's taking place he gets right in its face Ben 10 when lives are on the line it's hero time Ben 10 Ben: Seriously, Rook. You didn't have to come with me. [ Slurps ] Whatever this thing in London is, I can handle it by myself. Rook: Are you just saying that because you still have a childhood crush on Kai Green? [ Spits ] Even though she only found you interesting when she thought you were a werewolf? Gwen and I talk. Ben: It wasn't a crush, okay? I just thought she was different Rook: Well, I am excited to finally experience a different area of Earth. Did you know that despite its rainy reputation, the average annual precipitation in London is only 23 inches? Ben: Do tell. Rook: That is less than half the average annual rainfall in New York City. Ben: When I said, "do tell," I meant, "don't tell. " Rook: I hope English people make more sense in English than you do. [ Tires screech ] [ Monitor beeps ] Thanks for coming, Ben. I didn't know who else to call for help. Ben: Kai? Wow! You're so, um, taller Kai: Of course I am. It's been six years. You're taller, too, you goof. Ben: Yep. Way too tall to be a house pet. Come on, you had furry ears and a curly tail and [Scoffs] Never mind. I have to rescue my grandpa. Ben: Make that we have to rescue your grandpa. Ben: Kai, this is Rook. Rook: Miss Green, it is a pleasure to meet Kai: I just called you for backup anyway. Ben: Backup? I'm a superhero. I've saved the universe more times than I can count. Rook: The official count is three. Ben: It's got to be more than that. The point is, Ben Tennyson is nobody's backup. Kai: So you're not gonna help me? Ben: Well, we're already here, so Rook: I will wait in the truck. Ben: Wait. You were in Dr. Jekyll's lab? As in "Dr. Jekyll and Mr. Hyde"? It's just a story. Says the boy with the magic watch that turns him into aliens. The knights were taking my grandpa to a castle to help them get a sword. Ben: No problem. England only has what Two, three castles? Rook: More than 800. Ben: Oh. With swords in them? Rook: Substantially fewer. Ben: Ha! Rook: But it would still take a considerable amount of time to Guys! I already know where he is. One of the knights dropped this. Ben: "Howl's castle moving and storage"? Rook: No one is here. Ben: [ Sniffs ] [ Groans ] Well, somebody was here. Nice detective work, Sherlock. Rook: That is quite a compliment, Ben. Sherlock Holmes, while fictional, is highly regarded as the most Ben: Shh. Kai: New Omnitrix? Ben: Careful! You'll turn me into walkatrout or something. It's got a bunch of new aliens. So you couldn't even change into Benwolf if you wanted to. Ben: Oh, I can. I just choose not to. And, anyway, I don't call him Benwolf anymore. His name is, um blitz wolf er. Blitzwolfer? You just made that up right now. Didn't you? Ben: Did not! Rook: If I may interrupt your courting banter Are you kidding me?! No, no. Ben: That is so not Take that back. Rook: If I may interrupt your noncourting banter. Ben: That's better. No, it isn't. This is my grandpa's handwriting. Rook: Why would he draw a diagram of the statues in parliament square, and pair it with an old map of London? [ Beeping ] Ben: Hey! Quit doing that. Each statue represents a different London landmark. Rook: A hidden code. Ben: What's that one with the "X"? Real subtle. Says it's Oliver Cromwell. Grandpa has it corresponding with the Royal Greenwich Observatory. Rook: Something is not right. This map is dated 1860, but that statue was not installed until 1899. That's right, before then, there was a different statue of Cromwell in another part of the square. My grandpa would know that. He must be leading the knights to the wrong place on purpose. Ben: Then let's go to the wrong place, too, and kick us some forever butt. No!! My grandpa is risking his life to be sure the Forever Knights don't find whatever sword they're looking for. It's that important. He'd want us to get to it first. Rook: Are you sure that is wise, Kai? Once the Forever Knights realize your grandfather has tricked them, they Grandpa Wes says, "once a plumber, always a plumber. " He can take care of himself. Ben: So where was the old statue? Rook: Across the square. Kai: That would make the landmark it stands for Ben: Cool. Rook: Yes, it is. Many famous earthlings are buried here in Highgate cemetery Michael Faraday, Karl Marx, Douglas Adams. Kai: And they've all been waiting just for you. Ben: Ha ha. "The secret lies twixt hall and wall. " Ben: Which wall? And there's no halls. Rook: Hall and wall are capitalized. Does that not make them proper names? "Bartleby hall. " "Eunice wall. " This is it. [ Rumbling ] [ Gasps ] Four arms: Boo. [ Chuckles ] No sword. Just these two things. [ Grunts ] [ Gasps ] Unh! Wow. Your partner is really good. Four arms: I taught him a bunch of stuff. Sir Morton: Apparently not to look out behind ya! [ Grunts ] Take over. I'll save these. Sir Morton: [ Grunts ] What? Four arms: [ Grunts ] Rook: [ Grunting ] Sir Morton: Your girlfriend fights better than you do. Four arms: She's not my girlfriend. And hey! [ Grunts ] Forever King: Stay your hand! All of you If you value his life. Don't listen to him, Kai. [ Beep ] Forever King: The Oculata, if you please. The Oculata? Grandpa, the sword they're searching for can't be Forever King: The sword of Sigurd, of Beowulf, and of Arthur. Anyone anywhere who wielded it in battle was unstoppable. It is known by a hundred names around the globe, but you perhaps know it as All: Excalibur. Ben: That's just another story isn't it? Forever King: With Excalibur in hand, so shall I restore the Forever Knights to our rightful dominion over the world. No alien will dare set foot or tentacle on Earth ever again. Ben: Those were pretty slick moves back there. What was that? Some kind of secret navajo fighting technique? Yeah, it's called judo. I took classes after school at the mall. Ben: So, where we going anyway? Forever King: The Oculata were devised by scientists loyal to the Forever Knights. When placed atop the two towers of Westminster palace on the night of a full moon, such as this, the Oculata reveal the location of the vault of Britannia, where Excalibur has lain dormant since last used to defeat Napoleon at Ben: Dude, I just wanted to know where we're going. Nobody asked for a history lesson. Forever King: Take these two with you to Victoria tower. The Red knight and I will escort Mr. Tennyson and his girlfriend to Elizabeth tower. Kai: He's not my boyfriend! Ben: She's not my girlfriend! And where's Elizabeth tower? Forever King: How can you of all people have never heard of Big Ben? Ben: Pssht! Of course I've heard of Big Ben. Giant clock can't miss it. Rook: Actually, Big Ben refers to the 16 and a half ton great bell inside the Kai: Psst! Don't correct the crazy bad guy. Rook: I was correcting Ben. Okay then. Forever King: Enough with the playful banter. I have an invincible sword to claim. Ben: Ben 10 on Big Ben? How awesome is this? A million awesome. Well, it is. Forever King: Ah, it shan't be long now. The doorway to the vault of Britannia. [ Cellphone beeps ] There's going to be adistraction in exactly 10 seconds. When it happens, you've got to fly down there and get to the sword first. Ben: A distraction? What kind of [ Bell chiming ] Forever King: Aaaahhhh! What are you waiting for,ben? Go get the sword! Hurry! Ben: Come on, Omnitrix. Give me anything that can fly. [ Beeps ] Blitzwolfer: Blitzwolfer? Now? [ Groans ] [ Squeals ] My sensitive ears. Whoa! Ah! Whoa! Sir Morton: What in blue blazes is going on over there? Who is guarding the prisoners? What's this tech called again, son? Rook: A Prototool, sir. I sure wish they were invented when I was a plumber. Blitzwolfer: Hate to have to do this to you, man. A robotic ninja is a terrible thing to waste. [ Both grunt ] Well, that was Rook: Close. I will hold him off, Magister Green. You make a run for it. Looks like that's not an option. [ Grunts ] [ Screams ] Blitzwolfer: Kai! Kai: Ben! Aah! Blitzwolfer: [ Grunts ] Listen, Omnitrix. If this doesn't work, I'm really gonna need something that can fly. Kai: Good boy. Blitzwolfer: [ Squeaks ] Yeah. [ Beep ] Forever King: Ah, young love. Hmm. Now, if there are no further interruptions, I should like to go claim Excalibur and rule the world. Ben: Like I'm going to let that happen. Forever King: Now, if there are no further further interruptions, what say we continue our little adventure together? The suspense is killing me. Sir Morton: The doorway is sealed, sire. Ben: So, I couldn't have gotten in anyway. Good. I don't feel so bad for not making it here first. Kai: You didn't even try. Ben: Uh, who was busy saving your life? Whatever happened to "good boy"? Kai: That was for Blitzwolfer. Forever King: Children. [ Chuckles ] I am busy trying to become invincible here. Don't make me have to turn around. [ Rumbling ] Rook: I assure you, Magister Green, I have 100% confidence that Ben will never allow Excalibur to fall into the hands of the Forever King. Ben: The sword in the stone? Seriously? A necessary protective measure. Rook: Only one who is worthy can remove it. Forever King: Or one who has a superstrength serum. [ Groans ] [ Panting ] Ben: Yeah, I don't see this ending well. This is no joke, Ben. Ben: Relax, Mr. Green. I've got this. Superhero. Rook: 90% sure. Forever King: [ Grunting ] Monstrous King: From this day forward, I assume my rightful place, not merely as King of the Forever Knights, but as King of the entire Earth. I hereby claim thee Excalibur mine! [ Grunts ] I said I hereby claim thee mine! [ Grunting ] [Grunting] You! Transform into an alien and remove the sword from the stone. Ben: The King of the Forever Knights asking for my help? Monstrous King: The sword. Or their lives are forfeit. Ben: Pssht! Drama King. Okay, give me some room. - No, Ben. - Rook? Rook: 80% sure. Monstrous King: [ Snarls ] Hurry up. Ben: All right, all right. Keep your shirt on. [ Beep ] Four arms: [ Grunting ] Rook: Back to 90%. Monstrous King: Do it! Four arms: If it's so easy, you do it. [ Beep ] Humungousaur: [ Grunting ] [ Grunting ] This is one sword that's staying in the stone. Monstrous King: [ Grunts ] No, no, no! This must be some kind of alien trick. Destroy them! Sir Morton: Milord? Monstrous King: How dare you question your King. Destroy them all! Rook: [ Grunts ] Humungousaur: Not gonna happen. Rook: [ Grunting ] There is something you do not know about the Prototool. [ Prototool whirs ] You are holding it backwards. Humungousaur: Come on. We're getting out of here. Monstrous King: No. No one leaves without the leave of the Forever King. [ Grunts ] Humungousaur: Yeah, that sword is never coming out of that stone. Monstrous King: No one leaves without my leave. Humungousaur: [ Grunts ] Rook: Magister Green! [ Grunts ] Rook: Now what you want to do is What I've been watching you do all night. [ Grunts ] Humungousaur: See? When you do that, it makes me not want to go easy on you anymore, dude. I hope Kai didn't see that. I got to get me one of these. Aaaaaaaaaaahh!. . Did it just. [ Grunts ] Rook: Fluid pressure equals force over area. Ah, I got nothing. We can't keep wasting our time fighting or none of us will make it out of here alive. Sir Morton: A knight always obeys his King. Your King has become a powerhungry monster literally. Monstrous King: [ Grunts ] Humungousaur: Destroying us all is not going to get you that sword. Cause and effect, man. Learn it. Live it. Monstrous King: [ Grunts ] Sir Morton: Very well. Temporary truce of necessity. I think I found a way out of here. Sir Morton: She's good. [ Gasps ] Sir Morton: Indeed it is an exit of some kind, though we know not where it leads. Anywhere that's not here. We just need some leverage. Rook: Please use this instead. Well, this is unexpected. Kai: Is Rook your new King? Sir Morton: No. Just force of habit. [ Grunts ] Sir Morton: Success! When next we meet, enemies shall we be once more. Rook: Aw, a moment ago, I was your King. Everybody out! Ben! Change back into you. We found an escape hatch. Humungousaur: You hear that, crazy face? Time to go. Come on. After you. Monstrous King: Spare me your charity, Tennyson. I am the most powerful Forever King of all time, and you are but alien filth. Humungousaur: [ Grunts ] [ Beep ] Ben: [ Coughing ] I hope Kai didn't see that, either. Didn't see what? Ben: Dang it. Monstrous King: [ Roars ] Ben: [ Grunts ] Rook: The knights are not here? They could've been flushed out anywhere along the river. Kai: Or flushed someplace way worse. Ben: [ Chuckles ] Uh, gross. Ben, Rook, thank you for your help. Rook: It was an honor, sir. Kai: Yeah. Plus, it was great seeing Benwol I mean Blitzwolfer again. Ben: [ Chuckles ] Figures you'd say that. And it was kind of nice to see you again, too, Ben. Ben: Girls are weirder than any alien.