An American Benwolf in London

An American Benwolf in London is the forty-fourth episode of Ben 10: Omniverse.

Plot
In the sewers of London, England, Kai Green and Wes Green walk into the laboratory of Dr. Jekyll, whom they both thought wasn't real. Wes picks up the formula that transformed Dr. Jekyll into Mr. Hyde. Suddenly, Sir Morton and the Forever Knights arrive and the Forever King Joseph Chadwick explains that they need the formula. Wes throws explosive chemicals at them and breaks the vials of the formula, but he soon is taken down by the Forever Ninja. He tells Kai to run and Kai manages to escape, avoiding an attempted capture by Sir Morton. One of the Forever Knights gives the vial of the Mr. Hyde formula to Chadwick and Chadwick tells the Forever Knights to bring Wes to the castle, where he is needed to acquire a sword. Kai watches her grandfather being taken away and she takes out her cell phone to call Ben.

In the Proto-TRUK, which is flying over the ocean, Ben tells Rook that he didn't need to come to London. Rook believes that Ben still has a crush on Kai, also saying that he got that information from Gwen. Ben insists that it wasn't a crush, saying she was "different". Ben and Rook eventually arrive in London, where they meet up with Kai. Kai only wants them as backup to save Wes, but Ben says that he can handle it. On the road, Ben is surprised to hear that Dr. Jekyll and Mr. Hyde were real and Kai says that the Forever Knights were taking her grandfather to their castle to get a sword. Kai then gives Ben a piece of paper, showing where the Forever Knights have taken Wes and it leads to Howl's Moving and Storage. Ben, Rook, and Kai look around in the castle to find any leads. Kai notices Ben's new Omnitrix and wonders if he could still transform into Benwolf. However, Ben says he doesn't call him "Benwolf" anymore but, upon seeing Wolf Blitzer on the television, Blitzwolfer. Meanwhile, Rook finds some papers under a rug and Kai notices that it's Wes' handwriting. Rook wonders why he would draw the statues on a diagram with an old map of London. Rook notices something on the paper as Ben was messing with his Omnitrix and Kai holds Ben's wrist up to the paper which reveals an "X" mark. Rook notices that the dates of the statues don't match up due to the year they were made and Kai concludes that Wes lead the Forever Knights in the wrong direction. They all conclude that the sword may be in Highgate Cemetery.

In Highgate Cemetery, Rook continues reading the paper and notices that something is between "Hall" and "Wall". Kai then spots two gravestones of "Hall" and "Wall" and finds a stone with the symbol of the Forever Knights on it. Ben, as Four Arms, lifts up the stone, but finds two strange objects. Suddenly, arrows rain down, coming from the Forever Ninja. Four Arms throws the stone at him, but the Forever Ninja dodges it. The Forever Ninja attempts to attack Kai with its swords, but Rook blocks it using his Proto-Tool. Rook and the Forever Ninja continue fighting while Sir Morton attempts to attack Four Arms from behind. Kai takes the objects and leaves while Four Arms fights Sir Morton. Kai runs into a couple of Forever Knights and Chadwick suddenly appears with Wes in custody. Chadwick orders Ben's group to stand down threatening Wes' life and Four Arms transforms back into Ben. A Forever Knight gives the object to Chadwick and he says that it will lead to the powerful sword Excalibur. Chadwick says that with Excalibur, no alien will ever try to come to Earth again.

On the river, Chadwick and the other Forever Knights are taking Ben's team down to their destination. Ben asks Chadwick where they're going, but Chadwick speaks in a manner that confuses Ben. Eventually, they all reach a roof near Big Ben, where Chadwick orders Sir Morton to take Rook and Wes to Victoria Tower while he and the Forever Knight take Ben and Kai to Elizabeth Tower. At Big Ben, Kai is hooking up the object while Ben is excited to be on Big Ben. The moonlight hits the two objects, projecting rays of green light that point into the water, making a stone structure. Kai informs Ben that there is going to be a distraction and tells Ben to fly down and get Excalibur. Suddenly, the Big Ben starts to ring which causes all of the Forever Knights, including Chadwick and the Forever Ninja, to react in pain. Ben dials the Omnitrix, hoping to get any flying alien, but ends up getting Blitzwolfer and is immediately affected by the ringing of Big Ben. Big Ben eventually stops ringing and the Forever Ninja attacks Blitzwolfer with arrows. Blitzwolfer stops the arrows with his howling, but the Forever Ninja takes out his swords to attack. Sir Morton wants to know what's going on and asks the two Forever Knights, who are supposed to be guarding Rook and Wes. Rook and Wes are seen riding down a zipline using Rook's Proto-Tool. Meanwhile, Blitzwolfer knocks away the Forever Ninja, who lands in front of Rook and Wes as he prepares for another battle. Kai attempts to move away, but she falls off but grabs onto the clock hand. Blitzwolfer manages to save her and turns back into Ben. Chadwick appears before them and says that he is ready to claim Excalibur. Ben says that he won't let that happen but looks over and see that both Rook and Wes are surrounded by Forever Knights. Chadwick is now eager to claim the powerful sword.

Down at the structure, the Forever Knights are trying to open the door leading to Excalibur. Ben and Kai argue briefly and Chadwick manages to open the door using a ring. The group walks in and they notice that the sword is stuck in a stone. Rook says that only one is worthy of removing it and Chadwick drinks a vial of Mr. Hyde's formula, turning into a gorilla-like mutant. Chadwick tries pulling out Excalibur, but is unsuccessful. Chadwick then demands Ben to pull out the sword, threatening the lives of the others. Ben transforms into Four Arms, but he cannot pull out the sword. Four Arms transforms back into Ben, who then transforms into Humungousaur. Humungousaur tries pulling out the sword but ends up pulling the entire stone with the sword. Chadwick, having lost his patience, knocks away Humungousaur and orders the Forever Knights to destroy Ben's team. Humungousaur knocks away some Forever Knights, while the Forever Ninja manages to take Rook's Proto-Tool. Rook knocks the Forever Ninja down, who gets back up, pointing the Proto-Tool at Rook. However, it turns out that the Forever Ninja was holding it backwards and ends up shooting himself in the chest. Humungousaur grabs Kai and Wes and attempts to get away, but Chadwick throws a large rock at some water pipes and it seals the door at the same time, slowly flooding the room. Humungousaur attempts to break down the door using the stone with Excalibur in it, but has no effect. Chadwick jumps onto Humungousaur and starts to wrestle him down. Sir Morton and the other Forever Knights prepare to attack and Rook tosses Wes his Proto-Tool. Wes effectively uses the Proto-Tool to take down the Forever Knights while Humungousaur begins to gain the upper hand against Chadwick. Chadwick tosses Humungousaur into some more water pipes, which begins to flood the room at a faster rate. Chadwick continues to fight Humungousaur, while Kai and Wes are handling the Forever Knights. Kai knocks down Sir Morton, which causes his blaster to hit another water pipe and flood the room quicker than before. Kai grabs onto Excalibur, which actually causes it to move, while Rook attempts to stop the flooding. It is shown that Kai is worthy of Excalibur. Wes tells the Forever Knights that they cannot keep fighting or they will all perish. Chadwick knocks Humungousaur into yet another water pipe and Sir Morton agrees to a temporary truce to escape. Kai manages to find a way out, but it is locked. Fortunately, Rook uses Chadwick's scepter to pry open the lock and everyone starts to escape. Humungousaur is informed by Kai to escape and he tells Chadwick to follow them. However, Chadwick doesn't want to leave and tosses Humungousaur toward the exit, who transforms back into Ben. Ben escapes with the others back outside. On the bridge, Wes thanks Ben and Rook for their help. Kai kisses Ben on the cheek which, while walking away with Rook, makes him say that he thinks girls are weirder than aliens. Ben and Rook fly away back to Bellwood, while Chadwick is seen escaping with the Forever Ninja.

Major Events

 * Kai Green and Wes Green make their Omniverse debuts.
 * Blitzwolfer make his Omniverse debut.
 * It is revealed that the Excalibur is real and that Dr. Jekyll and his Mr. Hyde Formula were real as well.
 * Forever King Chadwick drinks the Mr. Hyde Formula and becomes a powerhungry gorilla-like beast.

Omnitrix Alien Debut

 * Blitzwolfer

Characters

 * Ben Tennyson (16 years old and 11 years old; only in Kai's phone)
 * Rook Blonko
 * Kai Green (first re-appearance)
 * Wes Green (first re-appearance)
 * Wolf Blitzer (first appearance; cameo on TV)

Villains

 * The Forever Knights
 * Joseph Chadwick
 * Sir Morton
 * Forever Ninja
 * Twin Knights

Aliens Used

 * Four Arms (x2)
 * Blitzwolfer (first re-appearance; accidental transformation)
 * Humungousaur

Errors

 * When Humungousaur battled the Forever King, one of the spikes on the Forever King's clothes were missing
 * The time displayed on the Big Ben clock tower changes between shots.

Allusions

 * This episode title is a play on the movie An American Werewolf in London.
 * The building where Rook, Ben, and Kai were investigating was named, Howl's Moving and Storage, which is a play on British children's novel Howl's Moving Castle by Diana Wynn Jones, as well as the film of the same name by Hayao Miyazaki. Also on the sign is the fire demon, Calcifer, from the movie.
 * There are a few Doctor Who allusions.
 * The angel statue in the cemetery bears resemblance to the Weeping Angel from Doctor Who.
 * In the same scene where they showed Howl's Moving and Storage, a telephone booth that resembles the TARDIS from Doctor Who can be seen at the entrance.
 * Kai Green's outfit bears a similarity to Lara Croft from Tomb Raider.
 * In the beginning of the episode Kai's grandfather mentions Robert Louis Stevenson, a Scottish novelist, poet, essayist, and travel writer.

Trivia

 * This episode was originally named Moonlighting.
 * Ben renames Benwolf to Blitzwolfer in this episode, after seeing Wolf Blitzer on the television.
 * This episode is one of the few episodes in Omniverse in which Rook's Proto-TRUK does not get damaged or destroyed.
 * Ben made a common mistake in thinking that Big Ben was the tower, until Rook corrected him. What Rook didn't mention was that the tower is called the Elizabeth Tower, as Dr. Chadwick cut him off before he had the chance to.
 * It's revealed that Kai is worthy to wield Excalibur.
 * The Forever Knights appear to be the basis for some myths and legends such a Dr. Jekyll and Mr. Hyde.
 * Rook revealed that Wes Green was a Magister.
 * Walkatrout's name is revealed in this episode.