Brothers in Arms is a Full Metal Panic!Alternate UniverseFan Fic written by Chris Ganale. It is set three years following the events of The Second Raid, and assumes that the novels never happened. In this continuity, Sousuke and Kaname started dating shortly after the Hong Kong incident, with Sousuke becoming a better pilot able to master the Lambda Driver and Kaname taking a civilian research role with Mithril. A new Specialist has been assigned to the Tuatha de Danaan, and in the intervening time, there's been an unsettling lack of activity by Amalgam. Has Mithril truly won peace, or is the dark shadow of Amalgam merely biding its time and waiting for the perfect opportunity?
Brothers in Arms provides examples of the following tropes:
A Mother To Her Men: Tessa, ridiculously so, to the point that she felt guilty for not having a Christmas present for her newest crewmember, who got there four hours before Christmas day. This trope is even pointed out by said crewmember
All Your Base Are Belong to Us: The all-out offensive against Mithril, including a devastating air/Arm Slave/ground attack that left Meridia Island an irradiated hellhole and, according to Wraith, flattened the Sydney headquarters in a cruise missile strike, and destroyed all other branches of Mithril except the American branch.
The assault by Amalgam on Washington DC, along with Soviet reinforcements.
Darkest Hour: The aptly-named "End of All Hope" chapter sees Mithril having been almost completely wiped out by Amalgam, the Meridia Island base nuked, the Tuatha de Danaan sinking with Tessa planning to go down with her, the Arbalest destroyed by the vastly-superior Belial, Kaname kidnapped by LeonardTestarossa, and Sousuke unconscious from multiple gunshot wounds, including several that could be lethal
Despair Event Horizon: Both Tessa and Sousuke had these. For Tessa, it was the nuclear cataclysm of Meridia Island, coupled with the crushing defeat at the hands of Amalgam, and the fact that her submarine had been crippled and was sinking. For Sousuke, it was all of the above, plus Kyouko being wounded in an enemy attack, getting trashed by Leonard's Belial, Arbalest being destroyed, and Kaname being kidnapped
Determinator: Getting wrecked in an Arm Slave battle and being shot multiple times, at least once in the chest, set Sousuke back about three days
Everyone Can See It: The attitudes toward Garon and Tessa in Mithril prior to Amalgam's attack. Averted in that both of them are aware of it, but aren't acting on it due to propriety, and then defied when Amalgam attacks and they come to mutual decisions that with the future being so uncertain, they better just make the most of it and hook up.
Exposition Fairy: Garon spends most of the first several chapters teaching Tessa about the Mandalorian way of living.
Expy: The Mithril soldier codename Wildfire looks and sounds like Captain Price, but Word Of God states that it's not him, since Price was stuck in a gulag at the time.
First Name Basis: When Tessa informed Garon that she'd rather be called by her nickname, he said that it felt funny to say and offered to call her the Mandalorian equivalent, Tel'ika. When explained that it was also a term of endearment, she said that they weren't close enough for him to call her that. Chapters later, when she says that he can call her that, he's already gotten used to calling her Tessa, but tells her that it'll be his private name for her.
Friendly Enemy: There was a notable beat when Tessa announced to the US Navy that they had been fighting alongside the Toy Box the entire time.
Goldfish Poop Gang: Venoms just aren't as scary as they used to be anymore, thanks to the Fairy Eyes sensor that shows Lambda Driver weakpoints and three years of Mithril training hard to counter Venoms.
Averted in the Washington DC invasion, where the US Army's M9s are curbstomped by the Venoms.
Gollum Made Me Do It: The methods by which Sousuke was forced to live while a child soldier in Afghanistan have produced an alter ego, Kashim, that he is all too aware of, and has gone to great lengths to keep from ever seeing the light of day. In order to cope with the sheer horror of the evil acts he'll have to commit in order to save Kaname, he decides to let Kashim loose, with assurance that Kashim also wants to save Kaname because they're both the same person
He Is Not My Boyfriend: Played as straight as possible in the third chapter, when Tessa very vocally denies that she has feelings for Garon. That stance lasts about two minutes.
Hope Spot: Once, during the battle at Meridia Island, after the Mithril forces and the US Navy beat back an air attack by Amalgam, which is then Jossed by a cruise missile strike and the arrival of Amalgam's Lambda-equipped Arm Slaves. Later, Sousuke has killed the terrorists holding the Jindai alumni hostage, and Kaname herself has just stomped five Venoms in the Arbalest. Then Kyouko runs smack into a claymore mine...
Ludicrous Gibs: What happens when you use 20-gauge deer slug on people at ranges varying from "fifteen feet" to "barrel-in-your-nose".
Made of Indestructium: Not completely indestructible, but the fake "Mandalorian armor" is built to withstand a ridiculous amount of punishment, with questionable design materials.
Mildly Military: Given the same treatment as in Full Metal Panic!. Garon does not like Commander Mardukas, is willing to say so, and doesn't even bat an eyelid at dating his commanding officer. Tessa seems to have a bit more trouble swallowing the fraternization problem, but in the end is just as quick to stop caring as she had been when she was trying to get with Sousuke in the source material.
Kashim himself makes a reference when asked if he has a 'has a plan'
Mundane Utility: Arm Slaves, top of the line combat weapons costing several million dollars each...used to cut down a Christmas tree.
Never Bring a Knife to a Gun Fight: In the desert battle in Garon's first mission, when the enemy Shadow pulls its BFS and jumps up to try to land on him, he just calmly shoots it while it's incapable of dodging.
Not So Different: Leonard tries to favorably compare himself to Sousuke this way, in reference to people he has ordered killed as opposed to Sousuke killing in battle, but it doesn't really go to his plan. Kaname really could give a damn less.
Now or Never Kiss: Garon was about to get into his Arm Slave to go fight against an all-out attack by Amalgam, led by a massive air force (it's always been rather back-and-forth about the effectiveness of an AS vs. an aircraft), which would then undoubtedly be followed by an Arm Slave attack. The enemy was expected to (and did) field Lambda-equipped Venoms, and the M9 does not have a Lambda driver of its own. With that in mind, Garon figured that he may as well.
Nuke 'em: Amalgam's backup plan for the West Pacific Fleet.
Kaname too. A sustained burst of 12.7mm fire changed their minds. All over the wall.
There Is Only One Bed: According to Garon, those wacky MolMolians thought that he and Tessa were farther along in their relationship than they really were
Title In: Every chapter and scene change is prefaced with a locator tag, of the format "Date (without year) and exact military time (always specifying what local time zone, sometimes using both local time and GMT), general location (such as city, state, country), and then a more specific location within the first."
Took a Level in Badass: While Sousuke was busy clearing out the terrorists in the school gym, Kaname had to fight nine Venoms by herself in the Arbalest. She wrecked them all in thirty seconds flat.