As petty chieftains and vassals plot against the monarchy, Kundavai tries to bring about political calm while Vandiyathevan crosses the Chola realm to convey a message from the Crown Prince Aditha Karikalan.This book falls within the historical fiction category. The power struggle that took place under the Chozha dynasty between AD 900 and AD 950 is the subject of this tale by Kalki Krishnamurthy. The three central characters in the story are Sundara Chozhan, the emperor, and his sons Arunmozhivarman (who became Rajaraja Chozhan later on) and Aaditha Karikalan.Arunmozhi Varman's elder brother Aaditha Karikalan delivers his father Sundhara two messages at the beginning of the story.During 10th-century in Thanjavur, the Chola dynasty rules prosperously in South India, under the reign of Emperor Sundara Chola (Prakash Raj) (the emperor of Chola empire), whose sons Aditha Karikalan (Vikram) (the crown prince and the commander of Northern troops in Sundara Chola's Reign) and Arulmozhi Varman (Jayam Ravi) aka Ponniyin Selvan are heading their conquests of Kanchi and Lanka, respectively for the empire. Aditha has defeated the Kanchi king Khottiga (Babu Anthony) in battle but spares his life despite Kottiga wanting a glorious death in battle, and not life of insult & humiliation.Sensing something is amiss with the courtiers, Aditha Karikalan sends his friend, the Vaanar Clan's prince, Vallavaraiyan Vandiyadevan (Karthi) (the brave, adventurous and sarcastic warrior prince of Vaanar clan) to investigate and relay the news to his sister Princess Kundavai (Trisha) (also known as Ilaiya Piratti) and Sundara Chola subsequently.Vandiyadevan reaches the fortress of Kadamboor and overhears the conspiracy devised by the treasurer and minister of finance, Periya Pazhuvettaraiyar (R. Sarathkumar) (from the Paluvettaraiyar clan who was respected for his valor and 64 scars he got in battles and Chinna Pazhuvettaraiyar's elder brother) and other ministers to stop Aditha Karikalan from ascending the throne and install his uncle Madhurantaka Chola on it. They believe Sundara's (who was the younger brother to the then king, slain in battle) ascension to the throne was a mistake and that the emperor should have been from the ruling family and now is the time to correct this historical wrong. At the time, Madhurantaka (Rahman) (Uttama Chola, the foster son of Sembiyan Mahadevi and Gandaraditya Chola (the erstwhile ruler of Chola Kingdom and Sundara's elder brother)) was a child and hence not suitable for the throne. Sundara was a caretaker only, but he decided to install Aditha as crown prince and not revert the throne to MadhurantakaAditha Karikalan swears vengeance against Nandini for his brother's death and heads towards the kingdom to destroy her. Meanwhile, Oomai Rani/Singala Naachiyaar/Mandakini Devi (Aishwarya Rai Bachchan) (who is Nandini's mother, the deaf & mute queen) , revealed to be a lookalike of Nandini, is shown swimming in the sea to find Ponniyin Selvan, to rescue him.