|Cover artwork||Karsten Schreurs|
|Publisher||Fantasy Productions GmbH|
|Era||Clan Invasion era|
|Timeline||9 April-22 December 3061|
|Series||Classic BattleTech Novels|
From the back cover (translated from German)
|“||The life of mercenary Mad Dog Maloy could be peaceful, except for the unknown party who wiped out her unit and destroyed their base. In her quest to find the perpetrators she is accompanied by her loyal Mad Cat 'Bugs' and the only other survivor of the massacre, Shin, an Elemental who once fought for the Clans. Together, the women stumble upon an intrigue that aims at destroying the Lyran Alliance. A race against time ensues and a hectic chase that brings them not only to the battle arenas of Galathea [sic] but also deep into the heart of the empire, to Tharkad...||”|
Around the beginning of the year 3061 one mercenary captain Craighton assembled a new mercenary unit on Outreach from people who had not met before. Under contract to FrictionTechInc. the small unit of altogether seven BattleMechs plus infantry was deployed to guard a copper mining operation on New Tucson, the fourth planet in the Lyran star system of Carstairs, a backwater desert world.
A few months later, on 9 April 3061, MechWarrior "Mad Dog" Maloy awakens in her downed and deactivated Timber Wolf (Mad Cat) and finds her nearby mercenary base destroyed. The only survivor is Elemental warrior Shin, whose battlesuit was trapped under a fallen Centurion at the onset of the attack.The base defenses were cleverly sabotaged by someone with intimate insider knowledge and access to their computer core. The same is found to be true for Maloy's Mad Cat which was rigged so that a single PPC blast was sufficient to deactivate it, but proves easy to repair.
Maloy and Shin discover Craighton's 'Mech standing hidden in a canyon near a supposed prospecting site. Craighton, who had been gunned down and shot through the knees, is found inside a nearby Star League bunker. The mortally wounded captain tells the women that the whole operation had been about finding and securing this old bunker; the "prospectors" had been Craighton's men. Trevor Argyle, one of their fellow mercenaries, betrayed the operation and stole four nuclear bombs from the bunker, leaving the fifth on countdown. The detonation is timed to coincide with the arrival of the next ore carrier DropShip in a few hours. Craighton manages to reset the countdown before passing out for good, buying Shin and Maloy enough extra time to escape the imminent explosion with the DropShip.
During transit, Maloy watches arena combat vids from Galatea where Shin suddenly recognizes the crest on one of the dueling 'Mechs (a red scorpion on a black field)—she saw the same crest on the 'Mech that downed the Centurion. Consequently, the women travel to Galatea, the former Mercenary's Star that has fallen on hard times, to follow the lead. Maloy partakes in arena combat, and they befriend a free tech named Randy Parker by saving him from a beating during a barfight. He becomes Maloy's de-facto personal tech after his small garage business is burned down in what may have been retaliation for the barfight, or just a random act of vandalism on the impoverished world.
Before long, they learn that the unit they seek was hired by a shady agent named Konrad Guntermann. Maloy and Shin raid Guntermann's large estate in his absence with their 'Mech and battlesuit, fighting down three 'Mechs in the process. They do not find anything helpful because the computers were wiped clean, but happen to free a strange prisoner, a roguish character who calls himself Saladin and tells an implausible story about how he was caught trying to burgle Guntermann's estate. Upon reaquiring Saladin's possessions from a secret vault they learn that he has copied Guntermann's files. Searching the files they find a blackmail letter from Free Skye separatists to the Archon of the Lyran Alliance that refers to New Tucson as a demonstration. Parker demands an explanation, and is told what happened there. Shocked, Parker finds that the files indicate the terrorists plan to detonate a nuclear device during a celebration of the assembled nobility and military leadership on Tharkad on 3 July, in ten weeks time. They realize that they probably cannot trust any authorities given the magnitude of the conspiracy. Almost out of money and wanted for their assault on the estate, they accept Saladin's offer to spirit them off world; Parker joins them as he has nowhere else to go and feels it is the right thing to do.
They make for Tharkad aboard the Free Rasalhague Republic smuggler ship Niflheim, which lands on Tharkad only on June 2, however, putting them on a tight schedule. The ever-resourceful Saladin has provided the team with false identities, and they assume the guise of a camera team. Maloy identifies Trevor Argyle in the city, which they take to mean the nuclear explosion is not yet imminent. The terrorists may aim to destroy not primarily Tharkad City but the Lyran government, establishment and military who will be having a ball in Asgard, the heavily secured HQ on Mount Wotan, around midnight. Deciding they need to go to the ball, Maloy reluctantly admits that she was LAAF once and still has connections that will allow her to attend. She selects Saladin to accompany her.
At the ball Maloy sees Trevor Argyle talking to General Marvaise, the supreme commander of the Freedom Theater. She retreats to the bathroom to avoid Argyle (who might recognize her), and shortly afterwards spots Marvaise going upstairs with a man she identifies as Konrad Guntermann from photos she saw on Galatea. Trying to eavesdrop on them, she overhears almost nothing besides a mentioning of "Hades" but is apprehended by Argyle. After a brief interrogation Marvaise orders her executed, but Argyle just knocks her out, ties her up and stows her into a cabinet. Saladin, after noting that Marvaise has left and seeing Argyle come down the stairs alone, suspects what happened and frees Maloy. The determine that the nuclear device must be parked in the underground garage in Marvaise's limousine which they proceed to steal. They pick up Shin and Parker, and while the car is chased by police cars, hovercraft and finally a Locust Parker frantically tries to disarm the bomb which is set to detonate within minutes. He succeeds and throws the detonator out of the car as they are racing through a shopping mall to shake off the Locust.
The protagonists escape from Tharkad aboard the Niflheim and, following the lead from Marvaise's conversation with Guntermann, move to Hades, an exhausted mining world in the Phalan system, to find the remaining three nuclear devices. Guntermann has bought a large abandoned industrial complex on the desolate world, obviously the terrorists' headquarters which is in the process of being relocated. By reactivating an ancient underground rail line, the protagonists manage to sneak the Mad Cat deep into the secured perimeter, blast through a wall and snatch away the three bombs just as they were prepared for transportation off-world. On their way back they are nearly overcome by enemy BattleMechs, only to have Lyran regular 'Mechs arrive on the scene. The battle turns three-sided when ComStar BattleMechs are suddenly combat-dropped into the fray and extract the bombs. As it turns out, Saladin is a ComStar agent, as was Craighton.
Maloy is later offered to rejoin the LAAF for her part in what happened, but she turns down the offer to stay mercenary together with Shin and Parker. On 22 December, Saladin sends them a message, offering OmniMech spare parts and good pay. They decide to work for him, but cannot agree on a unit name.
Written in German and exclusively published in that language so far, Duo Infernale does not technically meet the current criteria for Canon in the BattleTech universe. As an official product published under a valid license, it should be regarded as apocryphal instead.
- Mad Dog Maloy, a mercenary with a somewhat childish character who owns a Mad Cat OmniMech but refuses to reveal her background. It later turns out she is actually Maria Santini, daughter of the influential Lyran general Ernesto Santini. She captured the Mad Cat by kicking in the cockpit in some sort of death from above maneuver (dropping down on it from a ledge) in her Zeus. For this heroic but reckless act which cost her her 'Mech she was both commended for bravery and demoted and subsequently quit the LAAF, taking the Mad Cat with her. Since then she never spoke to her father again, who happens to lead the Lyran pursuit force from Tharkad.
- Shin was a Clan Smoke Jaguar elemental whose unit was wiped out to a man on Luzerne except for her. She was taken bondsman by Captain Craighton, and follows his last orders after his death. Cool and calculating, Shin has no qualms whatsoever about killing an innocent security guard who happened to endanger the mission, but she risks her life to save Randy Parker from a drowned car and is easily prepared to sacrifice herself if necessary. Having bonded with Maloy and Parker, she eventually agrees to become a mercenary alongside them after the completion of her last mission.
- Randy Parker served as a Com Guard technician in the Battle of Tukayyid, where he was wounded by shrapnel when Smoke Jaguar forces overran his post. He has run a small 'Mech garage on Galatea since 3058 and loses everything when it burns down, so he throws his lot in with Maloy and Shin and turns out to be surprisingly resourceful. At the conclusion of the fighting on Hades he rejects Saladin's offer to re-join ComStar.
- Saladin, a ComStar agent who oversaw the secret excavation operation under Captain Craighton (also secretly a ComStar agent). Following leads of his own, he is taken captive by Guntermann but then freed by Maloy, Shin and Parker, and decides to join them without revealing his true agenda.
- Trevor Argyle is the cover name of a man called Alistair by General Marvaise. An operative of the Free Skye movement, he betrays Craighton's mission which leads to the devastating mercenary attack. Something of a sadist, Argyle tells Craighton what he is planning to do before shooting him through the knees and leaving him to die in the imminent nuclear explosion which will wipe out the entire prospecting operation and is timed to also destroy the inbound DropShip with it, killing all witnesses and destroying all evidence. He later does the same to Maloy on Tharkad, leaving her alive (against Marvaise's explicit orders) to see the "premature sunrise" of the soon-to-occur nuclear explosion. He is arrested on Hades by loyal Lyran forces.
- King Crab
- Timber Wolf (Mad Cat)
- Warhawk (Masakari)