Trade-Off!

Trade-Off! is the tenth episode of the second season of Ben 10: Alien Force, and the thirty-sixth episode overall.
==Synopsis==
Darkstar convinces Kevin to join him in a quest for an ancient artifact with the ability to help them both escape their current degenerate states.
==Plot==
The episode begins with Darkstar studying in a warehouse when Kevin breaks in. Kevin wants to send Darkstar into the Null Void, but Darkstar quickly defeats him and says that he wanted Kevin to find him as both of their lives depended on it. Darkstar releases Kevin on the condition that he listens, and he says that he has discovered an artifact called the Dominus Librium that will transfer their energy in order to make both of them normal and neutralize their powers. However, it is on an island, and he needs Kevin to help him retrieve it. Kevin agrees. 
Meanwhile at Ben's house, Ben and Gwen try to call Kevin but he doesn't answer. Ben transforms into Jetray and he flies with Gwen to a mission. Darkstar and Kevin arrive at the island in a hovercraft and enter into the temple where the artifact is located, and it is flanked by statues. Kevin triggers a booby trap that brings the statues to life, and they attack him and Darkstar. Kevin and Darkstar fight with them and retreat. They enter into the temple. The statues are too large to follow them. While they are inside, Kevin and Darkstar discovered the Dominus Librium and Darkstar tries to retrieve it, but it is protected. Kevin goes up to it and is able to take it. Kevin is closed in two enormous hands of a statue surrounding the Dominus Librium.
Darkstar frees Kevin, who has the Librium. The temple starts to collapse and Kevin and Darkstar run, while barely escaping, and evade the statues. The island floods as Darkstar and Kevin get into their hovercraft and fly away. They enter into an isolated spot and use the Dominus Librium. The Dominus Librium works on Kevin and Darkstar and they are transformed back into normal, although their powers are gone. Then, Darkstar punches Kevin, takes the Dominus Librium, and tells him to stay away from him. That night, Kevin arrives at Ben's house and presents that he is human and powerless. Gwen is concerned about Kevin's black eye, but he lies about it. The team drives to a warehouse to fight the Forever Knights. Gwen tells Kevin to wait outside due to the fact that his lack of powers makes him a liability. While inside, Ben tries to transform into Humungousaur, but he transforms into Big Chill instead. Big Chill and Gwen fight the Forever Knights and Kevin comes inside and fights them as well. The Forever Knights attempt to flee, but Big Chill freezes their truck and transforms into Ben. Kevin reveals that he sabotaged the engine and Ben admits that Kevin is still an important part of the team even without his powers. Later, Kevin asks Gwen to do something with him, but she senses Darkstar in his aura and declines.
Gwen tracks Darkstar to the warehouse and enters inside. As Michael Morningstar, he explains the Dominus Librium to Gwen and reveals that he is using it as a substitute for his powers. Michael tries to absorb Gwen as Ben tries to contact Gwen, but he is unable to. Kevin tells Ben about his deal with Darkstar and Ben becomes angry and decides to go search for Gwen. Ben tries to transform into Jetray again to search for Gwen, but he transforms into Echo Echo instead and makes an army to split up, but Kevin knows where to go, and the Echo Echoes get in the car. Echo Echo transforms back into Ben, and they drive to the warehouse as Gwen fights Michael. Michael absorbs her shots with the Librium and finally grabs her with the Dominus Librium. As Darkstar starts absorbing her power, Ben and Kevin arrive and Ben transforms into Swampfire and attacks Darkstar, but his attacks have no effect on Michael. Darkstar absorbs Swampfire as well, but Kevin steps in front of the Dominus Librium and grabs it in order to send all of the energy back where it belongs and mutating him and Darkstar again. As Darkstar runs away with the destroyed Dominus Librium swearing revenge on the team, Gwen and Kevin help Ben up and they go to Mr. Smoothy.
==Noteworthy Events==
===Major Events===
*Darkstar returns and makes an offer to Kevin that will help them return to their original forms, only for both of them to revert back to their mutated forms.
==Characters==
===Main Characters===
*Kevin Levin
**Kevin's Alien Force Mutation
===Supporting Characters===
*Gwen Tennyson
*Ben Tennyson
===Antagonists===
*Darkstar
*Forever Knights
==Aliens Used==
*Jetray (cameo)
*Big Chill (selected alien was Humungousaur)
*Echo Echo (selected alien was Jetray)
*Swampfire
==Quotes==
==Naming and Translations==
==Cast==
==Allusions==
*The plot of this episode, mainly Kevin's role, is similar to The Thing from the 2005 Fantastic Four film, in which The Thing is assisted by Doctor Doom in reverting to normal from a disfigured form, but decides to re-mutate himself in order to save his friends from the same villain.
*Barrymore Theatrical Supplies is a nod to the Barrymore acting family, whose members include Lionel Barrymore, John Barrymore, and Drew Barrymore.
*The Witch-King of Angmar's mask from The Lord of the Rings: The Return of the King is seen in a couple of shots at the warehouse.
TO (1).png|Barrymore Theatrical Supplies
TO (19).png|Witch-King of Angmar's mask inside glass case
==Errors==
*In multiple shots throughout the episode, the mirror in the warehouse does not show the reflection of those in front of it.
*Jetray's hologram faces away from Ben.
*When Ben turns into Jetray, the two black stripes on his shoulders are missing for a few frames, just before he picks Gwen up from the ground.
*Kevin's coating is shown to be breaking while holding the Dominus Librium. However, in the next shot, his coating is shown to be intact.
*When Kevin enters Ben's house, he does not close the door on the way in. However, when he is about to leave, the door is closed. 
*After Big Chill reverts to Ben, there are no frozen Forever Knights in sight, but in the next shot, they reappear.
*After Gwen leaves to find Darkstar, Kevin doesn't have his black eye for the rest of the episode. 
*Although Kevin destroyed the door of the warehouse at the beginning of the episode, it is shown to be intact when Gwen reaches the warehouse. 
*In one shot, Kevin's shirt doesn't have the usual stain it has. 
*The hole in the sarcophagus that Darkstar broke during his fight with Kevin changes shape between shots. 
*When Ben says to Darkstar, "You may look human again", his mouth doesn't move.
*When Swampfire appears, his Omnitrix symbol looks flat and lacks the rim.
*After Kevin breaks the Dominus Librium, he and Gwen are sent flying at a considerable distance from Darkstar, but afterwards, both of them are shown to be lying closer to Darkstar.
*When Darkstar looks into the mirror, it is shown to be broken. However, when he runs away threatening revenge, the mirror is intact. 
*When Gwen and Kevin help Ben get up after being knocked out, Ben's hair is black. 
TO (14).png|Kevin breaks the door
TO (55).png|Missing reflection
TO (58).png|Missing reflection
TO (67).png|Hologram error
TO (69).png|Missing stripes
TO (209).png|Coating breaking
TO (211).png|Coating intact
TO (242).png|Kevin doesn't close the door
TO (258).png|The door is closed
TO (316).png|Missing Forever Knights
TO (317).png|Forever Knights reappear
TO (333).png|Door is intact
TO (345).png|Missing reflection
TO (359).png|Missing black eye
TO (361).png|Missing stain
TO (371).png|Hologram error
TO (405).png|Original sarcophagus hole
TO (408).png|Sarchophagus hole error
TO (416).png|Missing reflection
TO (419).png|Omnitrix error
TO (453).png|Missing reflection
TO (462).png|Gwen and Kevin are sent flying far from Darkstar
TO (464).png|Gwen and Kevin are lying close to Darkstar
TO (475).png|Mirror is broken
TO (477).png|Mirror is intact
TO (483).png|Black hair
==Trivia==
*The background music in the temple when Kevin and Darkstar take the artifact is the same music as in Ben 10 Alien Force: The Rise of Hex.
*The episode's title is listed as Trade-Off! on Amazon Prime Video and the Cartoon Network website, and also referred to as such in the script outline and by Len Wein. However, on the Ben 10 Alien Force: Volume 7 DVD and within the episode itself, it is listed as Trade Off.
*In an undated script outline:
**Kevin and Darkstar obtain the Dominus Librium on an alien world instead of on an island.
**Kevin tests his matter absorption powers shortly after being turned back to normal.
**During the fight against the Forever Knights, Kevin uses his ingenuity to emulate some element of his powers.
**Instead of sensing Darkstar on Kevin's aura, Gwen learns that Kevin and Darkstar worked together after Kevin lets it slip under his breath.
**Ben uses Jetray or Echo Echo to find Gwen and Kevin follows him in his car.
==Notes==
==References==
===Production Material===
====Script Outlines====
===Crew Statements===
====T.J. Collins====
====Len Wein====
===Cartoon Network===
es:El intercambio
pl:Coś za coś
pt-br:A Troca
ro:Dublura
Category:Episodes
Category:Ben 10: Alien Force Season 2 Episodes
Category:Ben 10: Alien Force Episodes
Category:Episodes Directed by Butch Lukic
Category:Episodes Aired Out of Production Order