It begins with the rescue. At least, that’s where the schism first appears, although it would not widen to the all consuming chasm it eventually reaches until much later.
Maedhros has always had a great need to control his surroundings, and this becomes something approaching pathological in the aftermath of his trauma. His brothers will obey him; despite any grumblings, they will fall into line without much trouble. But Fingon... Fingon is a rogue variable.
Fingon has seen him at his most vulnerable. Fingon keeps trying to reach out, to help him. Maedhros cannot bear it, knowing that someone has seen him so weak, begging for his own death. And so, he draws away and their once warm relationship frosts over.
Maedhros is no fool. He is weak at this point, both physically and mentally. And politically. The elves who crossed the Helcaraxë have become restless under Maglor’s interim kingship. They chafe under the rule of a betrayer and kinslayer. There is only one solution.
Maedhros plans it like so. He uses as precedent for his abdication the fact that Fingolfin exceeds him in age and therefore seniority. This simultaneously pacifies his brothers with the promise that the crown will default back to him as the next eldest should the worst happen to Fingolfin. The Noldor are a united front, ready to face Morgoth, and Maedhros has seen off any unrest by what he considers to be a temporary transfer of power.
Or so he thinks.
In hindsight, he was absolutely foolish to think that Fingolfin wouldn’t have thought of his succession, and moved to secure it.
Maedhros hears of the coronation far too late to do anything about it. It is winter in Himring, and the snow has been too thick for any serious travel from Hithlum for weeks. It is only when it thaws slightly that a messenger makes it through to inform Maedhros that High King Fingon expects him at his court at his earliest convenience.
The feeling of betrayal is far colder than even the chill of Himring the Ever-Cold.
Maedhros finds his mind racing immediately, thinking of plans and plots for a coup. He dismisses the messenger and retreats to his chambers where he finds an equally incensed Maglor.
The pair of them are unlike their brothers. They do not have their father’s temperament, explosive and confrontational. They have their mother’s, patient and calculating. Maglor knows as well as Maedhros their current position.
They are too weak for a coup. That is the unfortunate fact. They have lost too many strongholds in the Dagor Bragollach. They do not have enough popularity and political clout to survive the aftermath, even should they be able to overpower Fingon. All they can do is seethe in their impotence.
Maedhros leaves Maglor in charge of Himring and makes the perilous journey to Hithlum when the winter has thawed enough to make travel easy. He does not hurry, he is too late to make any meaningful difference, and he does not want to give Fingon a false impression of how their future relationship as king and subject will be.
The Dagor Bragollach has carved the land in strange ways and Maedhros finds previously safe paths to be impassable now. The journey is rather smooth, however, and Maedhros finds himself in front of Fingon far earlier than he might like.
They are cordial but cold with each other. Fingon initially makes stabs at their old camaraderie but he is no fool. After several frosty rebuffs, Fingon can see which way the wind is blowing and also retreats into formality.
There are no accusations. There are no explanations. Fingon does not intend to give them, and Maedhros would not wish to hear them. The damage has been done and it is irreversible. Fingon treats Maedhros as the vassal he expects him to be, and Maedhros treats Fingon with respect for his station. In public, their relationship appears to be professional if distant.
Maedhros does not tarry in Hithlum. He leaves the moment Fingon is done with him, and he turns everything over in his mind on his return to Himring. By the time he reaches home, he has formulated a thousand thousand plots and hypotheticals, and Maglor welcomes him with a warm meal and expectant ears.
They decide to bide their time as is the wisest option. They are nothing if not glacially patient. But they will not be completely idle. There is more than one way to undermine a ruler.
It starts small. Deniable. It starts with leaving Fingon out of certain affairs, with not informing him of troop movements, diplomatic agreements with Men and Dwarfs.
Fingon is not stupid. He knows he is being tested for weaknesses, judged on how he reacts. The Feanorians deal with him only through Maedhros and Maglor; Maedhros is not foolish enough to allow the certain open rebellion that would come from Celegorm and Curufin. But Fingon knows how things stand from the ironic deference of Maglor and the glacial cordiality of Maedhros.
Any friendship that was between them has gone now. What remains is something new, a mutual respect but not anything like warm camaraderie.
Fingon is not stupid, and responds back in kind to Maedhros’ blatant provocations. He passes over him for trade contracts, and court honours. He does not contact him for anything but key strategic moves in the war against Morgoth. He outwardly condemns the anti-Fëanorian propaganda that has begun spreading, but does nothing to stop it.
Fingon knows how important it is to keep Maedhros defanged so he cannot rebel against him.
Fingon’s official visit to Himring is again announced by a harried messenger who finds an unwelcoming reception at his destination.
Maedhros deliberately refuses to meet Maglor’s eye until they are in private. He knows Maglor well enough to predict exactly what he will counsel. It is too obvious to kill Fingon at Himring, far too obvious. It is not due to whatever remains of their friendship that Maedhros stays his hand, but because he is savvier than to kill a king in his own castle.
Fingon prepares, anyway, having had a similar thought. Whereas before he would have visited with relatively few guards for the journey, Fingon brings what seems to be his whole court, with enough guards to constantly watch his room and food tasters to ensure no nasty surprises.
There are no accusations. Maedhros and Maglor do not comment on the size of Fingon’s retinue. Fingon does not comment on Maedhros and Maglor’s undermining of his reign. No one sleeps easily.
When Maedhros receives the beleaguered Curufin and Celegorm after the debacle that is Nargothrond, he is not angry with them, not really. In fact, he is more pleased than anything else. Finrod would certainly have come to Fingon’s aid in a full-on power struggle, but Orodreth is a weak ruler and is unlikely to move against him.
This leads him to a plan, a coup without resorting to all-out rebellion. He plots for a great battle, a final hammer-blow against Morgoth that should hopefully kill two birds with one stone. After all, if Fingon’s forces were to take the brunt of the losses, who would suspect foul play? If Fingon were to tragically die on the battlefield, would the Noldor truly pick the absent Turgon over Maedhros for king?
The battleplans are tight and sound, and if Fingon finds any fault in them he does not say. Maedhros has to stop himself from grinning as the king agrees to the attempt at finishing the long war.
It is going according to plan. Fingon’s forces are being routed, Maedhros’ are still in fairly fine shape. Then, he hears the horns of Turgon’s host, and hears Fingon’s battlecry.
Maedhros freezes as he sees all his plots crumble into dust. The sounds of battle quiet against the ringing in his ears from his sheer rage. How did Turgon know? Who sent word to Gondolin?
He is almost glad when they are betrayed by the Men. This, this he can deal with. The battle is a bloody rout, but he can salvage one thing from it.
It ends like this.
He fights his way to where he last saw Fingon’s banner, amidst the glow of Balrog fire, and smiles as he finds Fingon gasping out his dying breaths amongst the ashes and in a pool of his own blood.
Maedhros treads his fallen banner into the blood as he approaches, and looks into Fingon’s eyes as the light slowly fades.
As his foot comes down on Fingon’s neck, he speaks loud enough for Fingon to hear him above the sound of battle.
“Long live the king.”