Following Sultan Murad's unexpected death, the Ottoman palace mourns and a new era begins. The question arises: will Mehmed or Orhan ascend to the throne? Despite İshak's opposition, Çandarlı supports Mehmed's succession, fearing unfortunate consequences. Mehmed, cautious of potential plots, sets out carefully with his servants. Constantine plans to hinder Mehmed, favoring Orhan's ascension. Orhan, closer to Edirne and with a better chance at the throne, rejects Konstantinos' offer for help, knowing it would not be welcomed. He faces an unexpected obstacle, Bali Bey, whose intentions remain unclear.

After conquering Dimitria Castle and defeating the Hurufi plague, Mehmed sets his sights on Constantinople. He tasks Evrenosoğlu with eliminating Orhan, aiming to trap him with a plan involving Hala Sultan. Meanwhile, Konstantinos, seeking to recover from his defeat, sends Sfrancis to attack the dervishes, hoping to prove the Turks cannot establish themselves. This draws the Ottomans towards him, and Çandarlı marches to confront Sfrancis. In the harem, Halime plans to kidnap Hala Sultan, who is awaiting her fate. The outcome of this plot remains uncertain.

During the Ottoman attack on Constantinople, Sultan Mehmed is wounded by a Byzantine soldier, leading to a temporary retreat. Sultan Mehmed, initially despondent, is inspired by Akşemseddin to renew his belief in conquest. He sends Ferhat Pasha as an ambassador for a prisoner exchange, but Ferhat is suspected of being a spy. Ferhat is captured and brought before the Sultan. The unfolding events will determine the fate of the Ottoman army, the revelation of traitors, and the ultimate success of the conquest.

Following the conquest of Constantinople, Sultan Mehmed worked to rebuild the city as a Muslim-Turkish homeland, uncovering and thwarting a major assassination plot while executing Prince Orhan, a longstanding threat to the Ottoman Empire. Determined to leave an Ottoman legacy, he initiated sweeping reforms, reshaped the administration, and commenced the construction of the Fatih Mosque, though an incident at the site deeply impacted him. Amidst these changes, a secret organization led by Plethon and Notaras began plotting, exploiting weaknesses to advance their ruthless goals, creating new challenges for Sultan Mehmed as he pursued his vision for the empire's future.

Mehmed is sentenced to lose his hand but is spared when Hristo, impressed by Ottoman justice, withdraws his case. This marks the beginning of Hristo's transformation. Mehmed, eager to usher in a new era, informs his viziers and sets his sights on western conquests. Meanwhile, Fatıma is given to Saltuk, and wedding preparations commence, but an unexpected stranger leads Fatıma into a new adventure, prompting Saltuk to search for her. In the harem, Mara bids farewell as she returns to Serbia with a new duty assigned by Sultan Mehmed, signaling the end of new beginnings within the palace.

After Prince Ahmed's death and Kurtçu Doğan's execution of Mehmed, Mehmed declares a new era, removing Kurtçu Doğan from Ocak Ağa and punishing the rebels. He reaffirms his goal of conquering Constantinople. Constantine, having exiled Notaras and brought in Sfrancis, tests Mehmed's stance on peace by sending an ambassador again. Meanwhile, Helena plans to marry off Constantine, seeking a suitable wife. In the harem, Halime's time ends as she passes away following Ahmed's death. Gülşah intercepts a letter sent to Mihriban, adding intrigue regarding Hala Sultan's involvement.

The Ottoman army, led by Zaganos, faced resistance at Dimitria Castle. When hope seemed lost, Sultan Mehmed arrived, inspired his soldiers, and ordered a final attack, aiming for victory. Meanwhile, the Hurufis, taking over provisions and spreading propaganda in the capital, face a new challenge as Mehmed is determined to protect his state from corrupt beliefs. Mara, seeking to undermine Byzantium through Hala Sultan, gains Mehmed's permission for her plan. Konstantinos, upon learning from his mother Helena why the castle was lost, plans to issue a harsh punishment to set an example.

Sultan Mehmed crushed a Janissary rebellion, executing Ali Haydar and his followers. He then sent Battal and Bali Bey to eliminate bandits, capturing Ferhat’s chamberlain, Beşir, and questioning Ferhat Pasha's loyalty. The Ottoman army attacked Constantinople with the Şahi cannon, creating a breach at the St. Romanos Gate. Despite heavy resistance and losses from Byzantine defenders, the Ottomans continued their advance. The battle's outcome would decide if Constantinople would become Istanbul.

Sultan Mehmed uncovers a dark organization lurking in the city, and as he strategizes to expose it, Agamemnon sets his own plans in motion—kidnapping Beyazıd under orders from Pontus. Meanwhile, Çandarlı methodically closes in on Nemesis and Agamemnon, hoping to beat Mehmed to the punch. Elsewhere, the Prince of Moldavia, sensing Ottoman power rising, attempts to unite kingdoms but faces resistance from Mara. In a desperate move, he takes Mara’s brother hostage, only to confront Vlad’s merciless nature as Vlad marches against him on Mehmed’s command. The unfolding events will determine who prevails in this tangled web of power, deception, and conflict.

Sultan Mehmed summons Çandarlı to the palace, unaware that his downfall is approaching as Zağanos plots against him. Capturing Notaras, Zağanos sets a trap to expose Çandarlı, ensuring Mehmed witnesses everything. Meanwhile, Vlad reunites with Mehmed and becomes part of his plans. Mehmed dispatches Evrenosoğlu and Bali to confront Pontus, the force behind Agamemnon, but they fall into an ambush. Çepni warrior Şamil rescues them, allowing Evrenosoğlu to demand answers from the Pontic emperor in Mehmed’s name. Now, the emperor must decide whether to submit to the Ottomans or resist in defiance.

Çandarlı, deceived by Zağanos, revealed everything to Mehmed, leading to his imprisonment. While Zağanos expected to be promoted, Sultan Mehmed unexpectedly summoned Mahmud Pasha, who had previously rescued the Evrenosoğulları. Mahmud's arrival marked the downfall of Çandarlı, who realized his fate was sealed. Meanwhile, Janissaries threatened to revolt to prevent Çandarlı’s execution, despite Kurtçu's attempts to calm them. The rebellion ensued, and a trial was held where Mehmed stood as the plaintiff and Çandarlı as the defendant before Hızır. Found guilty, Çandarlı was sentenced to execution, officially marking the end of his era.

On the night of his wedding, Mehmed embarks on a risky journey to Constantinople to save Zağanos, collaborating with an unexpected ally from the Byzantine palace. He also meets Urban, hoping to convince him to return. Mehmed's plans are shattered by news of his mother's death, causing him to question his father. His departure to Constantinople causes chaos in Edirne Palace, prompting İbrahim to confront Murad about Gülşah. Meanwhile, Helena and Notaras, aware of Turkish infiltrators, plan to capture Mehmed, which causes tension between Konstantinos and his mother Helena. The success of their plans and Mehmed's fate hang in the balance.

While campaigning against Karaman, Mehmed invites Evrenesoğlu Ali to handle potential issues in the capital, appointing him as the palace trustee. Çandarlı, remaining in the capital, plots to place Ahmed on the throne by manipulating Gülşah, facing obstacles from Halime who also aims to make Ahmed sultan. Konstantinos makes a risky offer to increase Orhan's allocation to quell discontent about Orhan's expenses, awaiting Mehmed's response. Kurtçu, following Çandarlı's orders, plans to intercept Mehmed and challenge him to pass under swords, risking conflict with the Janissaries. The unfolding events create a tense atmosphere, with Mehmed's decisions and responses critically shaping the outcomes.

Constantine reveals the truth to Mehmed when handing over Mara, exposing Çandarlı Halil's collaboration. Mara must decide whether to inform Mehmed or confront Çandarlı herself. Tired of political games, Mehmed sets his sights on conquering Dimitria Castle. Mara's return causes concern for Hala Sultan, prompting her to warn Mihriban. Mara devises a dangerous plan to expose Hala Sultan. The outcome of this scheme remains uncertain. Constantine seeks to bolster his city's security and considers seeking help from the Vatican, despite opposition from Helena and Sfrancis. The success of this unity and Constantine's plans hinge on overcoming these internal disagreements.

Mehmed's response to Plethon's peace offer and his complacent minister will impact the conquest. Zağanos brings news involving Evrenosoğlu, influencing Mehmed's stance. Mehmed's reaction to Grejuva's attack on the Janissaries will shape the general assault and its outcomes for Kurtçu. Çandarlı Pasha delivers crucial news from Constantinople, potentially altering decisions. Alperen, who joined the siege without consulting Evrenosoğlu, faces significant actions. Ferhat, backed by Çandarlı, aims to secure the Rumelia Beylerbeylik seal and win the Sultan's favor. Demetrios' motivation against Mehmed is in question upon his return. Nadia, jealous of Anna and Guistiniani's relationship, plans an attack, potentially impacting Guistiniani's motivation.

After the assault on the Walls, Mehmed's decision will impact the course of the conquest. Kalender's mention of a brave raider to Mehmed hints at a potential game-changer for the conquest. Orhan's aide in Constantinople and Mustafa are revealed as spies, affecting Mehmed's side and prompting Ferhat to take action. Meanwhile, Janosh, motivated by revenge from the Kosovo War, may disrupt Mehmed's plans. Çandarlı Pasha's schemes for Kalender Ağa and Ferhat Pasha aim to strengthen his influence over the Sultan. The new danger awaiting Bali and Hamza tests their resolve. Constantine, under siege and pressure, makes moves to defend his city. Giustiniani's emotional connection with Anna could impact his motivation and effectiveness in defending Constantinople against the Turks.

Mehmed, determined to take Constantinople, casts a new hawk cannon and digs a tunnel for underground advance. Satılmış Ağa helps overcome obstacles in the tunnel. After the martyrdom of his spy Mustafa, only Fatima remains to provide crucial war-changing news to Mehmed. Guistiniani, after securing help from the Pope, brings aid to Constantinople with John Grant. Mehmed must decide how to stop these aid ships. Battal, seeking revenge for his murdered family, targets Janosh. Whether Battal will succeed in killing Janosh is uncertain. Notaras disapproves of his daughter Anna's relationship with Guistiniani, preferring her to marry Konstantinos. Anna's suicide disrupts Notaras' plans, creating uncertainty about her survival and Notaras' next move. Kalender, consolidating power, faces opposition from Kurtçu, leading to a conflict that will influence upcoming events.

Sultan Mehmed assigns Admiral Suleyman Pasha to stop the Pope's aid to Constantinople. Mehmed watches the naval battle from the shore. Satılmış Ağa helps overcome a large rock, allowing Mehmed's attack plan to proceed. Mehmed orders his staff into action, with Battal Bey, Saltuk, and Satılmış Ağa taking on a dangerous mission. In Byzantium, Constantine is betrayed and wounded by Anna, who is imprisoned. Nadia plans revenge against Byzantium and Guistiniani. The tension between Kurtçu Doğan and Kalender rises, with Kalender seeking the position of Janissary Agha and Kurtçu angering Mehmed. The outcomes of Suleyman Pasha's mission, Mehmed's attack, and the internal conflicts in Byzantium will shape the fate of Constantinople.

Mehmed, recovering from a defeat, prevents an epidemic in Rumeli Hisarı with Kurtçu's help, earning Kurtçu the Sultan's pardon and foiling Kalender and Ali Haydar's plans. Kalender seeks Çandarlı's support to replace Kurtçu, leading to a radical new plan. Ferhat Pasha orders a raid on the Sultan's caravan carrying a cure for the epidemic. Battal and Bali Bey are dispatched to stop Dugin and his men. Ishak Pasha grows suspicious of Ferhat Pasha, who tries to deflect suspicion by claiming to save Mustafa. On the Byzantine front, Guistiniani's soldiers join Salvador's troops. Demetrios announces his intent to marry Anna to the senate, potentially altering the balance in Byzantium, and awaiting Konstaninos' reaction.

Murtaza and the rebels receive punishment, causing unrest in the headquarters. Mehmed's harsh justice affects the army and Kurtçu's stance is crucial. Akşemseddin meets Harry in the prison camp to maintain balance between the çeris, raiders, and volunteers, impacting his relationship with Mehmed. Hızır Çelebi investigates Baltaoğlu's murder amidst rising tensions, while Francesco's decision in the Byzantine world influences the conquest. Harry, suspected of murder, faces divided suspicions, with Çandarlı trying to clear his name and his journey with Zağanos Pasha potentially altering his standing.

Mehmed captures Plethon, who refuses to betray anyone during his interrogation, leading to Mehmed’s final judgment. As new regulations reshape the palace, Beyazid, intrigued by his father’s tales, escapes and encounters Agamemnon. After killing Saltuk and Fatima, Agamemnon sets his sights on Hızır Çelebi, aiming to destabilize Ottoman justice by luring him into a trap. Meanwhile, Beyazid’s disappearance sparks panic in the harem, prompting Mehmed to turn the city upside down in search, while Bahar grapples with overwhelming fear.

Prince Mehmed, ambushed by the poor, fights fiercely as İshak approaches with his men. Mehmed later returns to Edirne and moves his harem to Manisa, where he receives a letter to Gülşah prompting a journey to Karamanoğlu. Murad deteriorates after Hüma's death, causing concern for Çandarlı, who contemplates measures for the state's future. Mehmed, aware of the situation, leaves Şehabeddin in Edirne. In Byzantium, tensions between Konstantinos and Helena intensify as Konstantinos prepares to make significant changes, with Helena and Notaras posing major obstacles.

After ascending to the throne, Mehmed confronts Halime for attempting to kidnap Ahmed and Çandarlı for his alleged complicity. Halime faces a choice: implicate Çandarlı or remain silent. Mehmed establishes a new order in the palace and must decide on the Grand Vizier. In the harem, Bahar becomes the chief haseki, marking a new era. Hala Sultan's unexpected arrival disrupts the harem's order, and her first move targets Halime. Gülşah is placed under Bahar's influence by Mehmed. Çandarlı plans a new strategy against Mehmed, using Piri Pasha's arrival to pit the Ottomans against Karaman. The unfolding events set the stage for further political intrigue and power struggles.

A cannon explodes near Mehmed, turning the area into chaos. Quickly removed, Mehmed faces more disappointments, including a fortress raid and Mara's kidnapping, pushing him to demand accountability from the betrayer and the careless. Konstantinos, having kidnapped Mara, tries to convince her to marry him, but Mara stands firm. The outcome of this struggle remains uncertain. Orhan seeks revenge on Bali, whose fate is in question. Hala Sultan, having created space by removing Mara from the harem, has new goals. It is uncertain whether Bahar and Gülşah will counter her moves or if Hala Sultan will dominate the harem.

Mehmed holds Baltaoğlu Süleyman Pasha accountable for Guistinianni's entry into the city, facing a potential execution. Çandarlı may try to persuade Mehmed to change his mind. In the harem, Prince Beyazıd's discomfort might continue due to the attention given to Mustafa. Meanwhile, the Balinese pursuing Demetrios in Mora face various challenges and obstacles, with Demetrios and his wife Theodore plotting their own strategies. In Constantinople, the arrival of Guistinianni's soldiers will impact the city's atmosphere. Both Ottoman and Byzantine sides prepare for tactical battles before the siege, with Mehmed planning his moves towards the city's walls and gates. The responses of Zağanos, İshak Pasha, and other Kubbealtı ministers to Mehmed's strategies, as well as the defensive plans of Konstantinos, Notaras, and Giustinianni, will shape the upcoming conflict.