Inspector 13

Inspector #13 is the forty-fourth episode of Ben 10: Ultimate Alien and the twelfth episode in the third season.

Plot
A Techadon master visits Kevin's garage, looking for an Omnitrix signal. Kevin attacks, ending up unconscious. Gwen later finds him clad in sports clothes as they promised Julie they'd help her practice, Kevin points out the need to hunt down the weapons master as he is a bigger threat than every Techadon they've ever faced combined.

Meanwhile, Ben and Julie are playing tennis, Ben isn't doing well, but then he transforms into Echo Echo to play better against Julie. Inspector 13 arrives on scene, he wants to study the Ultimatrix so he captures Ben. He takes Ben on his ship, telling him that he was sent to investigate a series of Techadon unit failures and wishes to use the Ultimatrix to revolutionize Inspector 13's industry, so he tries to cut off the Ultimatrix, but Ben tells him that a security measure in the Ultimatrix will cause it to self destruct if he cuts it off, so Inspector 13 hacks the Ultimatrix instead, easily breaching the security measures and unlocks the Master Control.

Gwen and Kevin teleport aboard. Gwen destroys of the security machines the Inspector 13 sends at them, for they have no defense to Anodite powers, but they are adapting to her. Ben tries transforming, but it backfires, causing Gwen and Kevin to transform into Diamondhead and Jetray respectively. They are released off of the ship, falling down to Earth. Diamondhead encases herself and Jetray in a mana crystal, allowing them to land safely.

Inspector 13's ship is damaged in the battle, so he flies to the Techadon Factory in downtown Bellwood to use its technology and materials for repairs. Ben is able to escape into the factory, and the Weapon Master pursues him.

Ben uses some Techadon hands from the incomplete Techadons to try and defeat Inspector 13. In the battle, Gwen and Kevin called Ben that they want into normal, so Ben changed them. Gwen, Kevin and Julie drive to the Techadon Factory, Gwen and Kevin are transformed into Clockwork and Wildmutt. Wildmutt is barely able to avoid traffic as he crashes just outside the Techadon Factory, which can't be moved. Clockwork remarks that the military has been trying to get into the factory for weeks, with no results. Ben tries to use the Ultimatrix as the Inspector 13 captures him. Clockwork is transformed into Humungousaur and Wildmutt into Way Big. Just before they both try to break in the factory, Ben presses the Ultimatrix, causing Humungousaur to turn into Upchuck and Way Big into Nanomech. Upchuck is disgusted by her powers with Nanomech trying to make her eat through the factory wall. She tries to, but the factory repairs inself and is impervious to Upchuck's energy balls.

Nanomech flies through the hole Upchuck created before it regenerates after her attack. He attacks Inspector 13 as Upchuck arrives and eats the bonds holding Ben. She and Nanomach are transformed into Rath and AmpFibian and start destroying the Techadons, as Ben uses voice command mode to make the Ultimatrix recognize him, turning Rath and AmpFibian back to normal. Ben turns into Four Arms, and punches Inspector 13, defeating him. Ben, Gwen and Kevin force the ship to take off, and Ben, Gwen, Kevin and Julie return to downtown Bellwood.

Gwen tells Ben that since Kevin and she got Ben's powers, Ben might have gotten Gwen and Kevin's powers during that time. Ben feels frustrated that he fought the Techadon master with his human skills instead of seeing if he had Anodite and Osmosian powers.

Major Events

 * The Master Control is unlocked on the Ultimatrix.

Ultimatrix Alien debut

 * Clockwork (used by Gwen)

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Julie Yamamoto

Villains

 * Inspector 13
 * Techadons

By Ben

 * Echo Echo
 * Terraspin
 * Four Arms

By Gwen

 * Diamondhead
 * Clockwork (first appearance)
 * Humungousaur
 * Upchuck
 * Rath

By Kevin

 * Jetray
 * Wildmutt
 * Way Big
 * Nanomech
 * AmpFibian

Errors

 * When Gwen appears in Kevin's garage she has a sweat band on her left wrist then when Kevin tells her to power up while holding her right wrist and left arm the sweat band is gone
 * After the Techadon Master's ship arrived, Echo Echos' rackets were gone.
 * When it first showed the tennis scene the Ultimatrix's black communicator screen disappeared it then came back after he attempted to hit the tennis ball.
 * In one scene, when Julie was punching Techadon Master's ship door, the door was gone.
 * Inspector 13 says No one has seen us (weapon masters) and lived. He said this although he knew Kevin and Julie had tried fighting him and survived.
 * When Ben jumps out of the way of one of Inspector 13's rays, he jumps onto the ground behind a pillar. However, a second later, he is seen quite a height above the ground.
 * It is strange that Inspector 13's ship did not give the 'intruder alert' when Nanomech and Upchuck entered.
 * When Ben is strapped to the 'torture table', the position of the shackle on left hand keeps changing (for a while, the Ultimatrix is partially inside the shackle, then it comes out and goes back in).

Trivia

 * The aliens Gwen transformed into don't have a female appearance like in Gwen 10.
 * It is revealed that Echo Echo can also duplicate the things he is holding.
 * It is unknown why Ben did not simply transform when the master control was unlocked as seen in War of the Worlds: Part 1 when the master control is unlocked Ben can transform with voice commands.
 * The Weapon Master referred to the aliens by the names of their home planets (e.g.: Geochelone Aerio as "Aldabran" and Human as "Terran").
 * According to Geoffrey Thorne, Inspector 13's plasma cage and Gwen's powers scrambled the Ultimatrix into thinking Kevin and Gwen were both Ben and so the device transformed them both.
 * According to Geoffrey Thorne, Clockwork debuted in an "offscreen adventure" before this episode.
 * Ben refers to the original series episode, Secrets in this episode when he says Been there, done that to Inspector 13's instructions of imagining an army each equipped with an Omnitrix\Ultimatrix.