Final Fantasy VII
Barret Wallace is the leader of the current incarnation of the rebel group called AVALANCHE. He is first encountered during their assault on Mako Reactor No. 1, which is also where he meets Cloud for the first time.
While Barret doesn't question Cloud's credentials in combat, he doesn't trust Cloud because of his Ex-ShinRa roots. This is made even worse by Cloud's apparent lack of care, but he's thankful for Cloud's assistance when faced with the Guard Scorpion.
Following the successful mission, the group head back to Sector 7 to regroup at the 7th Heaven bar, which is their headquarters.
Assault On Mako Reactor No. 5Barret assembles the group in their secret underground lair below 7th Heaven after being greeted by his adopted daughter Marlene. They see the coverage that their explosion caused and the next morning Barret informs them all that they will be attacking Mako Reactor No. 5 next.
After some fun on the trains, the group eventually arrive at the Mako Reactor. However, to their surprise they were expected. President Shinra is there to welcome them, although his pleasantries don't last long, as he sets the Air Buster on them.
When the Air Buster is defeated, it explodes causing Cloud to hang precariously on the edge. Barret tells Tifa that there is nothing they can do and they leave Cloud to fall into Sector 5.
The Collapse Of Sector 7Shortly after arriving back from the mission, Barret interogates a suspicious looking man, who reveals the name "Don Corneo". Tifa goes to investigate against Barret's wishes, but it ultimately leads to nothing as ShinRa attack the Sector 7 plate support before they can give Barret the information about the impending attack.
The members of AVALANCHE fight valiantly against the ShinRa attack, but they ultimately fail and the Turks manage to collapse the plate, which destroys Sector 7. Barret, Cloud and Tifa manage to escape, but Biggs, Wedge and Jessie were not so fortunate.
When they reach safety, Barret loses his cool because of all the lives that have been lost. Cloud attempts to soften the blow by telling him that Marlene is safe, with Aeris' mother, Elmyra.
Infiltrating The ShinRa BuildingAfter finding out that Aeris got captured while trying to protect Marlene, Barret agrees with Cloud that they should go and rescue her from the ShinRa building. He also thinks it is the perfect time to strike back with some vengeance.
After eavesdropping on Hojo talking about some new test subjects, Barret figures out that Aeris must be being held in Hojo's lab. They rush there and Barret breaks the cage that's holding Aeris and Red XIII.
They are ultimately captured though, only for them to escape. After fighting two bosses in the lift of the ShinRa building, Barret crams everyone into a truck and with the assistance of Cloud, escapes to the outskirts of Midgar.
He is then rather disheartened as everyone seems to elect Cloud as the new leader of the expedition, instead of him.
A Past Filled With ShameWhen the party venture to Corel, Barret is greeted with a less than hospitable reception by its residents. Barret tries to apologise but nobody listens and one resident even hits him.
He explains that in the past, Corel was a mining town. However, when he heard about ShinRa's Mako Reactors, Barret convinced the town's citizens that they should give up coal mining and let ShinRa build a reactor.
ShinRa built the reactor, but one day there was an explosion. ShinRa assumed that the Corel residents were to blame and completely destroyed the town. They also killed many of the residents including Barret's wife, Myrna. Barret also thought he had lost his best friend Dyne, as Barret was forced to let go of him when his arm was shot by Scarlet.
Another Man With a Gun ArmThe party are arrested in the Gold Saucer after a man with a gun arm is accused of killing people in the Battle Square. Barret protests his innocence, claiming that there is another person with a gun arm, but they don't believe him.
After Barret lost his arm during the incident in Corel, he decided to get a gun grafted to his elbow. While he was having the operation performed though, the doctor mentioned that she had performed the operation on another man, but on the other arm.
Barret is reunited with Dyne inside the Corel Desert Prison, but although Barret wishes to reconcile, Dyne doesn't. He lost everything during the attack, including his wife Eleanor and Marlene, his daughter. After Barret tells Dyne that Marlene is still alive, Dyne claims he wants to destroy everything and take her with him.
Following this statement, Barret reluctantly defeats Dyne in battle and after giving Barret a pendant that belonged to Eleanor, commits suicide by jumping off a cliff.
Facing Certain DeathAfter the group are captured in the Great Northern Crater, Barret and Tifa are signed up to receive the death penalty live on TV. When he finds out that Tifa will be executed first, he pleads with them to let it be him, but they don't listen.
This is quite fortunate, as Cait Sith arrives and manages to free Barret from his captors. They are unable to free Tifa from the gas chamber though and Barret reluctantly leaves Tifa behind following Cait Sith's grand plan.
From Zero To HeroReports are heard about Huge Materia being stored in Corel and Barret goes to investigate with the rest of the party. When they arrive they find out that the Huge Materia has already been loaded onto the train and has departed.
They manage to catch up with the train and make their way to the front, where they attempt to apply the brake to slow it down. However, the brakes don't work and the train starts speeding up instead of slowing down!
Fortunately, Barret and Cid manage to stop the train literally inches from the town and the people of Corel are exceedingly grateful. He has officially redeemed himself in their eyes and they inform him that they're going to dig to escape Meteor, as they're coal miners at heart.
What Am I Fighting For?When Diamond Weapon attacks Midgar, Barret is worried about Marlene. Cait Sith informs him that she is safe, but the two get into an argument about Barret's reckless terrorist acts.
While Barret doesn't see Cait Sith's point of view, when Cloud asks Barret what he is fighting for, he suddenly sees what Cait Sith was saying and feels remorse for all that he has done.
He realises that he is fighting to protect Marlene's future. For this reason, Cloud tells Barret to visit her before the final confrontation with Sephiroth so that he is in the right frame of mind when the time comes.
Final Fantasy VII: Advent Children
Barret is off searching for a new energy source, and leaves Marlene Wallace in the care of Cloud Strife and Tifa Lockheart. During the film he actually leaves a message for Cloud informing him that he's found a large oil field, which they could use.
Barret's physical appearance in the film is quite limited as he is only really shown in the battle towards the end of the movie against Bahamut SIN. During the fight, he uses both Big Shot and Ungarmax and gives Cloud a boost up to attack Bahamut SIN in the air.
An interesting fact is also that Barret visited Shalua Rui shortly before the events of Advent Children to upgrade his arm, so that it could transform between types without having to swap attachment.
Before Crisis: Final Fantasy VII
Having firmly believed that the age of coal was over and that Corel town should move with the times, Barret was a firm advocate of ShinRa's new Mako Reactor. Infact, he actually helped with the construction of the reactor.
Ironically, Barret also aided ShinRa in the removal of AVALANCHE who were hindering the completing of the Mako Reactor, by providing useful information and man power to the Turks efforts.
This ultimately lead to AVALANCHE bombing the reactor causing ShinRa to reduce the village to ashes, although Barret never knew who the culprits of the explosion were.
Dirge of Cerberus: Final Fantasy VII
Barret makes two brief appearances during Dirge of Cerberus, with the first being when he is called upon by the World Regenesis Organisation to assault Midgar.
Barret organises the whole the assault against Deepground and spearheads the attack on the ground in a van, which holds Cloud's motorcycle in the back.
There Won't Be A Single Sucka Standing!Although Barret is briefly heard when Tifa has a phone conversation with Vincent, he isn't next seen until he uses Satellite Beam to take down one of the reactors in order to help with the battle against Omega Weapon.
He is then seen standing with his old friends, looking on as Vincent fights against Omega Weapon.