Tabitha was born in Roanoke, Virginia. She is depicted as a rebellious but normal teenager in her first appearance. The daughter of divorced parents, Tabitha's mutant powers manifest at age 13, and her parents immediately show their disgust, her father even beating her. She runs away from home, giving herself the alias "Time Bomb", and meets the cosmic entity known as the Beyonder. He brings her to Charles Xavier, headmaster of the School for Gifted Youngsters, who ignores her to combat the Beyonder. Just before she can commit suicide over this second rejection, the Beyonder stops her, taking her with him on his cosmic trip. The Beyonder confronts the Celestials, and at her behest, returns Tabitha to Earth. She helps the Avengers ambush the Beyonder. She leaves the battlefield when she learns that the Beyonder felt betrayed by the actions of "his only friend".
Living on the streets, Tabitha becomes involved with Maurice "Tiger" Antonini and, after he threatens Tabitha and murders her friend, Gina, she uses her powers to kill him. The villain known as the Vanisher then recruits her for his band of thieves called the Fallen Angels, and she officially takes on her codename "Boom Boom". She eventually betrays the Vanisher, calling in the help of X-Factor, whom she stays with afterwards. Tabitha's former teammate in the Fallen Angels, the alien Ariel kidnaps the Angels to her home planet, to be experimented on by her planet's scientists. Ultimately, though, she can't go through with the plan and helps them escape. The Angels return to Earth and go their separate ways. Tabitha is kidnapped by the Right, an anti-mutant organization. Tabitha, X-Factor, and other mutants regain their freedom. Later, Tabitha joins her fellow X-Factor trainees as the X-Terminators. The team battles N'astirh's demons. During her tenure with the team, she convinces Rictor not to commit suicide.
After the events of the Inferno saga, Tabitha and some members of the X-Terminators, Rusty, Skids and Rictor, join the New Mutants. During her time with the New Mutants, Tabitha falls in love with her teammate, Cannonball. When the team is transported to the mythical realm of Asgard, it is partially through Tabitha that the team is able to foil a plot to kill Odin. They encounter the man known as Cable, and when he starts to mentor the team, Tabitha gains greater control of her powers. Tabitha is captured by Stryfe and the Mutant Liberation Front, but is rescued. During "The X-Tinction Agenda" crossover, in which the mutant-hating country of Genosha begins attacking mutants in the United States in retaliation for an earlier fight with the X-Men, the Genoshan Magistrates kidnap Boom-Boom and some of her teammates, namely Rictor, Wolfsbane and Warlock, transporting them to Genosha.
The incident receives international coverage, and Tabitha's father is even interviewed, still voicing his disgust for his daughter. Although stripped of their powers, she and Rictor manage to escape, whereas Wolfsbane had been processed as a mutate slave. Warlock does not survive. On the streets of Genosha, Rictor and Tabitha meet Jubilee, and Tabitha and Jubilee's similar attitudes clash. They eventually make their way to the Genoshan citadel, where the other X-Teams gather to defeat Cameron Hodge, the villain who orchestrated the entire ordeal. Once returned to the United States, Tabitha spreads the ashes of her friend Warlock over the grave of Warlock's best friend Doug Ramsey, a New Mutant that had died.
The New Mutants team, under the continued tutelage of Cable, is soon reformed into X-Force. The team undergoes a revamp, employing new, more aggressive methods. During this time, Tabitha acts on her crush on Cannonball, and the two have a relationship. Although questioning the team's new methods, Tabitha sticks with the team, rechristening herself "Boomer". She battles the Brotherhood of Evil Mutants alongside her new team in one of their early missions. During the "X-Cutioner's Song" crossover, the X-Men confront X-Force, whom they believe are involved in an attempted murder of Professor X. Boomer was defeated in combat by Rogue, and taken prisoner by X-Factor. When her team is jailed by the X-Men, Cannonball chooses Tabitha to fight with him alongside the X-Men, against the Mutant Liberation Front. Soon they discover that Rusty and Skids have joined the MLF, and Boomer's jaw is broken in combat by Skids. After this event, Tabitha is confronted by Cannonball's ex Lila Cheney, who gives the couple her blessing. Showing how serious Cannonball is himself, he takes Tabitha along for a vacation on his family's farm, during which they are confronted by the Gamesmaster and the Upstarts, and team up with the New Warriors to defeat them.
Eventually, the team's headquarters are blown up twice, and without a home the team moves back into Xavier's mansion. Shortly after, Cannonball graduates into becoming an X-Men member, and their relationship waters down. Seeking comfort, Tabitha spends most of her time caring for the lobotomized Sabretooth, also confiding in him. Her teammates attempt an unsuccessful intervention. Sabretooth reveals that he's faking the ordeal however, and fully healed, escapes by deceiving Tabitha into destroying his bonds. In his escape, he eviscerates the X-Man Psylocke, who barely survives her wounds. In an effort to deal with the guilt from this incident, Tabitha travels home to visit her father. The two reconcile, but in a fight with Sebastian Shaw and Holocaust, her father is critically injured. With more guilt on her mind, Tabitha underwent a radical change, renaming herself "Meltdown", designing a new costume and gaining better control of her powers along with a more brash and assertive attitude. This new attitude is displayed by Meltdown when she fights the Blob, threatening to kill him, and eventually having two time-bombs explode near his eardrums. With Cannonball spending his time with the X-Men, Tabitha grows closer to Sunspot and they have a short fling. Cannonball finds out and is initially angry but reconciles with both his friends, rejoining X-Force in the process. After an incident in which the High Evolutionary shut off all mutant powers, Tabitha and Cannonball come close to rekindling their relationship.
In the meantime, the sudden power loss really hits home for Cannonball, as to just how little they had been doing lately to help mutant-kind. He got back in touch with Pete Wisdom, and together they devised a plan for reactivating X-Force as a covert strike team. Meltdown, along with Warpath and Bedlam, agreed to enter into this new arrangement, and they took up residence in an abandoned Nevada Hulkbuster base for extensive retraining for martial combat and the use of their powers. In particular, Tabitha learned how to direct the explosive force of her power into streams of guided energy, and was also heavily trained in computer hacking and manipulating digital information. The revamped X-Force fought the shadow wars that other people couldn't even see, against the likes of meat-spore storm-troopers, mutagenic bioreactors and assassins who carried the mutant gene for murder. After she almost lost Sam to that last threat, Meltdown confessed she couldn't bear to see him die, and the two of them became lovers again.
While most of their missions were successful, they weren't without their share of troubles - Wisdom was apparently killed on their first mission back in San Francisco since leaving, and on two separate occasions their enemies tried to kill them in massive explosions. The team's undercover status turned out to be a weakness, though, for some new organization consisting of mutants that wanted to get rich and famous thought the name was up for grabs. After buying legal rights to use "X-Force" as their name, this group went public and soon became popular. When the original X-Force learned of this, they came out of hiding and confronted the new guys about the name and violating the original concept behind the team, it was already too late. Apparently, the original X-Force disbanded after this, retreating from their recent hardcore offensive stance on mutant issues. Sam and Tabitha also went their separate ways.
Weapon X and the X-Force mini
When Cable discovers hints regarding the existence of a revamped Weapon X program, one designed to use mutants to hunt down and intern other mutants, he creates an organization to investigate the program and the existence of its internment camp, Neverland. He dubs the organization the Underground, and invites Meltdown to join his elite group. Ultimately, Cable's Underground group is joined by Weapon X agent Brent Jackson, who hopes to stage a coup against the project's Director and has formed his own resistance group with fellow agents Washout, Marrow, Wild Child, and Sauron. Jackson betrays the Underground team however after the coup is successful and alters/wipes their memories of the events. Sometime thereafter, Cable learns of another threat to mutant-kind, the voracious creatures known as the Skornn, a creature that was going to threaten Earth.
He gathers and reunites X-Force in order to deal with them. Meltdown is among the former members he recruits. While both Cannonball and Sunspot are also involved in the conflict, Tabitha’s feelings for either weren’t brought up. However, she reveals to have learned a new trick with her mutant powers when she channeled one of her time bombs through Shatterstar's blade straight into the chest of a seemingly unbeatable opponent. After the Skornn was also defeated, some of X-Force remains together, assisting Cable on Providence, an island nation he created. Afterwards, she helps them attack the headquarters of the Black Box, though the occupant turns out to be a robot. Tabitha is one of the few mutants who retain her powers after the events of M-Day.
Shortly afterwards, after an initial period of wild arrogance, Tabitha seems to mellow out and settle back into her earlier, more bubbly personality. She even develops a tendency to use chat room-like short-hand when speaking out loud, such as "OMG," "ZOMG", and "OH NOES!". She also begins to start saying "Tick, tick, tick, tick-- BOOM!" when using her powers. Tabitha also grows her hair long and eschewed her codename and re-appears as a founding member of Nextwave, a new off-beat and more than slightly satirical super-hero team featured in an eponymous comic book series created by Warren Ellis and Stuart Immonen. The Highest Anti-Terrorism Effort, or H.A.T.E. (a subsidiary of the Beyond Corporation©) formed the team. Tabitha Smith's new team includes other second-string characters taken from Marvel limbo, including Monica Rambeau (formerly Captain Marvel, the leader of the Avengers), Elsa Bloodstone, Aaron Stack, and new character The Captain. Everything seemed on the up-and-up until Tabitha began snooping around, and discovered the marketing plan of the Beyond Corporation, H.A.T.E.'s financial backers. It turned out that Beyond Corp evolved out of the former terrorist cell known as S.I.L.E.N.T., and was planning to use H.A.T.E. and Nextwave to further its own sinister agendas.
Tabitha brought the files she stole to the squad leader, Pulsar, and Nextwave hijacked a Shockwave Rider transport ship and defected from H.A.T.E. Tabitha and the others fought against their former employers, and defended the country from the unusual WMDs unleashed by the Beyond Corporation on the general populace; the first biological weapon was revealed to be Fin Fang Foom, a giant lizard which clambered from underground and proceeded to wreck the building site. After putting an end to the threat of Fin Fang Foom in Abscess, North Dakota, Nextwave moved on to Illinois. Tabitha manages to subdue Mac Mangel, a corrupt police officer who had been taken as a host by the Ultra Samurai Seed. The Ultra Samurai metallic shell disintegrates, leaving Mangel crushed. Upon learning that he was a police officer, Tabitha and Aaron began to beat Mangel before Rambeau intervened. The team were later attacked by 'The New Paramounts', a team consisting of Not Brand Echh characters including Forbush Man, The Inedible Bulk and Charlie America. Forbush Man attempted to use his mind control powers on Tabitha, but was shocked to find they didn't work on her as she apparently has no mind. Tabitha subsequently killed Forbush Man, saving her teammates. When they awoke, she explained "The little guy did something to your heads. I gave him the explodo because I am clever." Not long after, they eventually exposed and destroyed the true mastermind behind S.I.L.E.N.T.
Tabitha moves to San Francisco to help with the X-Men's new relocation plans, and has resumed using the codename Boom-Boom. While shopping in San Francisco she confronts the mutant Nuwa. Forced by the Beast to confront Nuwa through research, instead of strength alone, she discovers by a thinly veiled parody of MySpace and Facebook called FaceSpace the true nature of Nuwa's sedation powers, and nullifies them by assuming strong quantities of stimulants, namely the caffeine of an unspecified number of espressos.
Kidnapping, death and salvation
Tabitha is later kidnapped along with Surge and Hellion by the Leper Queen and her Sapien League. The Leper Queen attempts to inject her with a modified version of the Legacy Virus, a virus which had been cured years before that afflicted mostly mutants, when the members of X-Force arrive to try and save her, Surge and Hellion. After Cyclops refuses to wait long enough for Wolverine and Domino to kill the Leper Queen, they are sent through time to help Cable, leaving the Leper Queen and Tabitha all alone. The Leper Queen reveals to Tabitha that she had intended using X-Force to kill her, since Bastion will not let her commit suicide and that the plan was for Wolverine to kill her and rescue Tabby. The Leper Queen shoots Tabitha between the eyes, saying that X-Force "failed them both".
After X-Force's mission in the future is complete, X-23 emerges from the timestream seconds before the Leper Queen is about to kill Tabitha and shoots her in the head. With the Leper Queen dead and Boom-Boom saved, X-23 collapses in exhaustion just as a team of H.A.M.M.E.R. agents storm the building, providing Tabitha with medical care while taking X-23 into custody. The agents are given the order to take a genetic sample from Tabitha and then kill her, but one agent plans to rape her before killing her. She is saved from death yet again by Warpath, who kills the agents before they are able to defile her and takes her to the X-Force safehouse to see if she remembers anything else about her kidnapping.
Boom-Boom is later seen during the events of Utopia, amongst the mutants assembled in Nightcrawler's chapel as they all prepare to abandon San Francisco for the base that the X-Club has risen from the bottom of the ocean. She is among the first group of mutants teleported by Pixie to the new base. Boom-Boom was also one of the X-Men who defeated the invading Predator X's who attacked Utopia. Boom-Boom, Iceman and Colossus teamed up to defeat the first Predator.
Powers and abilities
Volatile Constructs: Boom Boom can create and launch bombs, explosives, and other volatile objects from her hands, that range from small to giant scales. These "bombs" can explode with concussive force. She can produce marble-sized "bombs", which have little concussive impact and which she uses for playing pranks. She has produced "time bombs" ranging up to the size of beach balls, which, when they explode, can smash tree trunks and even metal objects. The amount of concussive impact depends on the size of the bomb she creates, and she can, at least to some extent, control the amount of time until it detonates. After training with X-Factor and adventuring with X-Force, she has gained increasingly greater control over the energy she generates. She can now muffle the sound of the detonation to a limited extent and generate explosive energy as streams that respond to her thought directions. Now possessing greater control over her powers, she can even reabsorb the energy of non-detonated bombs and is no longer afraid to use her time bombs in nearly lethal ways.
In other media
- Tabitha appears in the X-Men: Animated Series as a young child, along with Rusty, Whiz-Kid and Skids in the episode "No Mutant is an Island".
- In the X-Men: Evolution animated TV series, Boom Boom was voiced by Megan Leitch. Originally one of the New Mutants, Tabitha had a troubled past and a criminal father. Her role in the series was significantly diminished afterward; she lived on her own and appeared mostly in the company of her best friend, Amara, AKA, Magma from the New Mutants.
- In Wolverine and the X-Men, Boom Boom was seen in the first episode as a captive of the MRD facility. She escaped with Wolverine and Beast's help, and help fight off their pursuers, along with fellow former captives, Dust and Pyro.
- Boom Boom was one of the mutants that Striker kept files on.