Part 1: Legacy of the Forge

Our heroes make their way towards Toshi Ranbo wo Shien Shite Reigisaho to meet with Tankenka the Imperial regent. However, once they arrive the see that the Lion and Crane armies are just about to engage hostilities. At the gates they encounter a group of lion Junshi, and their honourable conduct allows the heroes to add these to their travelling troupe. 
When they arrive in the location where the meeting is supposed to take place they learn that the imperial official has already deceased. The follow him in the afterlife where they see a host of spirits possessing both armies and degenerate the scene in an all encompassing slaughter, with no regard for sides. The spirit of Tankenka explains the Legacy of the Forge and gives the heroes a spell scroll to stop it. It's two prerequisites are: a battle of significant worth and a sacrifice in the ritual to return the Legacy. 
Knowing that Daidoji Uji will lay siege on Shiro no Yojin, the heroes quickly make their way to where this battle will take place.
Our heroes arrive to see that Daidoji armies are already preparing their siege. . With a quick decision from Hida Buruke they charge towards the Shiro no Yojin while the Lion general is assassinated from somewhere within the fortress. 
Once they start the ritual the heroes are suddenly attacked by Goju Ninja. A fierce battle ensues but in the end they succeed in returning the Legacy to the proper spirit realm. In hindsight  it is clear that The Lying Darkness was behind the summoning of the spirits from the Realm of Slaughter.
At the end of the battle, an imperial messenger delivers them the following letter:
A quick examination yields a hidden message, when folded correctly the letter reads: "Be careful in the Imperial court. Our Emperor is not himself. Great danger awaits all of you. Do not stay long in the forbidden City"

Part 2: The Sentaku Tribunal

The heroes arrive in the capital of Rokugan; Otosan Uchi. They are welcomed by Hida Kosuga, who governs the Kosuga district. He explains that their letter is no free pass into the Forbidden City but that they must apply to see the emperor trough the Sentaku tribunal.
The heroes relocate to the Karada district, governed by Hida Reitaan where they recieve the information about three possible Sentaku backers: Yasuki Maro, Daidoji Jikkyo and Otaku Geshiko. Each of these have their own idiosyncrasies and prerequisites before they will pledge to back the heroes.
Furthermore, the heroes are required to display their cultural skills by folding an origami crane.
By performing various tasks and investigating several options the heroes finally get the backing of several Sentaku members.

Part 3: The Emperor Retuned

Finally the heroes are allowed to enter the Forbidden City. They are summoned to court where they enjoy a lavish feast. Kuni Shidjiro is almost poisoned here but is warned by his Jade chopsticks. When Kyoshi and Yorito use their shadowsight they immediately see that the emperor has been compromised by the Shadow. However, at this point they get an uncontrollable urge to kill the emperor.
Meanwhile the heroes have received the new status of Emerald Magistrates. Yorito manages to suppress his feelings but Kyoshi starts casting a spell in the middle of court. This results in the entire group being arrested and thrown in jail. 
A week later, all are released and the magistrates learn further news about what transpired in court:

The Emperor stalked forward without warning, cutting off the sentence mid-query. His hand fell to his sword and he struck with Akodo precision.

Isawa Osugi’s headless corpse slumped to the ground. “Kolat,” Toturi the First whispered. The word reverberated around the silent court chamber with the force of an Imperial decree. He sheathed his blade with slow deliberate motions. A hundred courtiers watched in stunned silence as the Emperor of Rokugan gave his victim a disinterested glance. Without another word, he turned and sauntered out of the room.

Silence reigned in the Imperial Court long after the Emperor’s last steps faded into oblivion. Every samurai in the room was trained from childhood to navigate the treacherous waves of political intrigue, but their training had not prepared them for this.

“I had always heard of the Kolat as a myth,” Kitsu Sanetori said slowly.

“The Kolat is a myth,” Yasuki Tansa quickly interjected.

“They are peasant tales, myths of boogeymen and phantoms creeping in the night…” His voice trailed off into an embarrassed silence. No one stated the obvious: when the Emperor of Rokugan publicly named them, the Kolat were no longer a myth.

“We are fortunate the Glorious Emperor is ever vigilant,” Kakita Aihara murmured. His small voice was barely audible in the quiet room. “He has only just returned to us from his difficult ordeal, and he is already protecting the Empire from those who would threaten it.”

Sanetori smiled and his foot stamped the floor in approval. “The Emperor is a true warrior who will not hesitate to act! True Lion blood courses in his veins! Our enemies stand no chance, and no Kolat could ever stand his might.”

Shinjo Tanimuro smiled, but it did not reach his eyes. “You cannot defeat every enemy with your katana, Kitsusan. The Emperor’s disappearance was not solved with brute force but by the cleverness of our Otaku Battle Maidens. No one knows how much this… Kolat infestation… has spread. We should proceed with caution.”

Yoritomo Hogosha raised his wrinkled hands into the air with a theatrical flourish. Despite his advanced age, his voice rang clearly through the court. “You ignore the obvious! The Emperor has spoken clearly with his actions. The young Isawa was the pearl of the Phoenix Clan and she was a treacherous whelp. Their entire clan is suspect and they cannot be trusted. Surely now no one can protest the Mantis Clan’s rightful claim of our Imperial Charter. We will continue our venture into unaligned lands as per our mandate from the Emperor.”

The room silenced once more as all heads turned toward the Phoenix detachment. They shared quick glances, struggling to ignore Osugi’s cooling body. Finally, a young girl stepped forward and cleared her throat.

“Your armies march into Phoenix lands, Hogosha-san. They are Phoenix lands, and Phoenix ancestors tended to those lands. You cannot confuse the issue. We will not stand idly by while your tyrannical Champion attacks us.” Hogosha snorted. “Your brightest was a traitor, and the rest of your—”

“Enough,” Bayushi Muraisan shouted. “Your petty insults can continue soon enough, Hogosha-san. You cannot ignore the threat of the Kolat. We have heard the tales. We have heard of their strengths. They are our true enemies. The Scorpion stand ready to face them. Do you?”

After they learn about this events the magistrates confer about the nature of the Kolat, most of which is unknown to them at this point. Mitsurugi leaves to warn his wife-to-be and she explains much more about the Kolat.
However, when he returns to discuss what he has learned, that the Kolat is a powerful enemy of the Lying Darkness, suddenly the conversation switches towards the loyalties of the two shadow-tainted companions. Tempers flare up and katana's are drawn.
Kakita Yorito decides to leave his companions but Yasuki Kyoshi sees no such alternative as a solution. Realising his tool has been compromised, the Lying Darkness floods Kyoshi with shadow taint and transforms him into a shadow-beast.
A brutal fight ensues but in the end the magistrates are victorious and succeed in defeating the shadow...

Children of the Crane!

Hear me now, as I write my last letter to you.

Our Champion has commanded me to hold my ground at Bayushi Palace, but I will not. I have marched the army of Daidoji through beiden Pass, toward Shiro no Yojin and victory. Kuwanan-sama chases the Mantis. Though some say they only try to fulfill their charter of peace and marshal the unaligned lands, we of the Crane know that Yoritomo-sama seeks a greater prize – not gold, or silver, or gems, but Jade. And Kuwanan-sama will give his life to see that the Throne is safe from a petty upstart. And he is right to do so. But I cannot. I have spoken with the Mantis champion, and I know his ways better than any man. He seeks power, yes, but only as much as he can protect – and the Jade Throne is a prize too many men covet. It would be his, and gone again, before the sun set.

There is another enemy which must be stormed. The Matsu, confident in our weakness, have left their lands lightly protected, sending the mass armies to assault the Crab. Again, they attack helpless peasants and defenseless lands, as they did when they seiged lost Doji palace. This cannot be allowed. We must strike now, before they raise an army of black fiends and Oni, before the sorcerer they serve raises the head of his beast and sends it toward our children. My honor demands that we slay Okura, retake Shiro no Yojin, and return it to the hands of its rightful owners.

My ancestor, Daidoji Yurei-sama, swore to defend that palace, and my honor demands I fulfill his oath. Further, it is the duty of every Daidoji to protect Crane lands against the black grip of the Lion. Their Jade Champion, Kitsu Okura, is a blasphemy to his rank, and to the Empire. They are a soil upon the brow of the sacred land, one which I cannot allow to live a day longer. They must be destroyed, as they once tried to destroy us. If my life is forfeit, then I will gladly sacrifice it so that the Crane may rise. Once I have taken the palace and destroyed this blood Sorcerer, I will send my head to Niwa Shita no Kage Toshi in recompense for my treason.

Daidoji Uj

Most heinous assassination of Otemi's second while comiting seppuku
Since the grave events of the night before, all court activities have been cancelled. Only the Ikebana flower arrangement contest continues. 
By mid day, the heroes are expected at court to inform it of their findings and dealings with the Shadow. First the Unicorn Emerald Magistrates tell their tale of the Lion treachery they encoutered. They were hot on the heels of a Maho-Tsukai who escaped to Lion lands and hid in a local village there. the Magistrates assume the Maho Tsukai got aid from the local population.But before they were able to investigate the village, Jade Champion Kitsu Okura appeared. Kitsu Okura  was the first to hold the Mantle of the Jade Champion since centuries. But his victory at the championship was marred by rumors of dark deals being the source of his power. Okura unceremoniously ousted the Emereld Magistrates  from Lion lands claiming they had no juristiction. This and other rumours and events will prompt the Unicorn to send an army to Lion lands In order to force the issue.
Next, Kuni Rashomon presents his case, allowing Kuni Shidjiro to retell all the events involving the Shadow. However, Daidoji Uji voices the thoughts on this for most of the gathered clans. The Lying Darkness seems a minor problem compared to what is happening in Rokugan and mostly a Crab Clan problem. As such, Uji claims its is no different from the Shadowlands and thus a Crab responsibility. Futhermore Daidoji Uji presents his intentions to declare war on the Lion clan and retake Shiro no Yojin, The Castle of Vigilance. As his ancestor Daidoji Yurei had commanded him to do so in a dream.
Kitsune Ryoshei promises to look into the matter of the Lying Darkness.
Before more discussion can be held a gong sounds, announcing the time of Ikoma Otemi's seppuku. A light drizzle falls as the samurai completes his ritual but just as his yojimbo is about to strike off Otemi's head, the bushi is felled by an arrow to the neck. Shame and outrage erupt. Shidjiro spots a small, dark figure escaping in the woods. Misturugi goes in pursuit and manages to take the assassin down. She is a young and beautiful woman but immediatly tells Mitsurugi that this is all part of the plan and shows him a crane tattoo on her shoulder. Mitsurugi decides quickly to let her go.
Meanwhile Daidoji Uji takes the opportunity to shame the Lion emissaries further, claiming their dishonest conduct solicited the underhand ninja attack. Tempers flare and the Lion declare war on the Crane.

Yoritomo Masasue
Just before the botched seppuku ceremony Mitsurugi was approached by Yoritomo Masasue. He is a Bushi with a deep love for arts and philosophy who has read the transcript of Misturugi's  play about Emperor Tutori and the nature of Ronin. He is highly impressed with the work and asks Mitsurugi to write a new commissioned play for him that delves deeper into the topics of man, being responsible for his own fate and actions instead of the widely recognised machinations of fate by the Kami.
Although apprehensive at first, after a long debate and the exchange of idea's about the self-sufficiency of men and Masasue's guarantees of a receptive audience all over Rokugan. Mitsurugi agrees.
Meanwhile Kuni Shidjiro and Yasuki Kyoshi have been invited by Iuchi Karasu (who has gained the nickname "inside-out man" from the Crab magistrates). He has information on the Lying Darkness that he did not wish to reveal before the assembly. The Doomseeker explains more on the modus operandi of the Lying Darkness, who corrupts and claims people in high places in order to have spies everywhere. Karasu also tells a tale from when the Unicorn travelled the burning sands. In this tale, the Unicorn discovered that By shining light trough a cristal they could see when someone was taken by the Shadow. See the complete story here.

Fox Clan Temple of Ancestors
Kyoshi, taken by the Darkness
That night, the heroes convene to discuss their findings. Afterwards Kyoshi finds himself unable to sleep. He feels strange and when he returns from an unfruitful cleansing ritual in the woods, while using his Kuni crystal, he discovers that his features have vanished.
Even though he is loathing to do so, Kyoshi finds no alternative way but to seek help from his rival Kuni Shidjiro. The two meet and their conversation attracts the attention of Buruke and Mitsurugi as well. All can now plainly see the evidence before them. Kyoshi has been infected by the Darkness.
Unsure what to do the heroes discuss this problem. Kyoshi cliams he has full control of his actions and since previous attempts (Kakita Yorito's stain) have failed to cut away the taint with the Kuni Tanto, kyoshi returns the Kuni Crystal and they decide to leave it at that, pending new information.
The next morning, Kuni Rashomon declares that our heroes cannot continue their investigations by remaining in Crab lands as magistrates and declares Kakita Mitsurugi as the new leader to perform covert operations away from the Crab. Accompanied by this surprising news is a letter from the right hand of Chancellor Takuan, Tankenka (see below).The letter asks the heroes to come to Toshi Ranbo wo Shien Shite Reigisaho or Violence Behind Courtliness City, also just named Toshi Ranbo by most.
Tankenka also speaks of a common denominator who is behind several insidious plots to raise animosity between the clans.