Saint Vaisampaayana continued to tell Janamejaya, the story of Mahabharata.
After taking leave from all the elders in the Kuru Assembly, Sri Krishna came out of the assembly building. All the elders in the Kuru assembly accompanied him to give send off. At the main gate Daruka was waiting with the chariot. Sri Krishna took leave from all the elders with folded hands and requested them to remain there.
Dhrutarashtra told Sri Krishna "Krishna! You have, , indeed, witnessed all with your own eyes. Nothing now is unknown to you. Seeing my endeavour to bring about peace between the Kurus, and the Pandavas, in fact, knowing the state in which I am, you should not entertain any suspicion regarding me. I have no sinful feelings towards the Pandavas. You know what words have been spoken by me to Suyodhana. The Kauravas and all the kings of the Earth, also know, that I have made every endeavour to bring about peace." said Dhrutarashtra.
Then Sri Krishna told Baahlika, Bheeshma, Drona, Krupa and other elders "'You have yourselves witnessed all that has happened in the assembly of the Kurus, how wicked Duryodhana, like an uneducated wretch, left the court from anger, and how king Dhritarashtra also described himself to be powerless. With the permission of you all, I shall now go back to Yudhishthira and tell him what had happened." said Sri Krishna.
Then he mounted the chariot. Some of the elders also followed his chariot. All of them went to the apartment of Kunti. Krishna told her what had happened in the Kuru assembly and asked her to convey her message, if any, to Pandavas. Then Kunti said thus:
"Kshatriyas should trust their vigour and valour and other ways of living are prohibited for Kshatriyas. Foolish people live as they like in some way or other. Pandavas tried for reconciliation but in vain. Kshatriyas have to live with the prowess of their arms. If Arjuna will not show his vigour and valour in the battle, he will be belittled. How Bhima has accepted for this mediation proposal. Krishna! Pandavas might have follishly thought about mediation. How you have come here at their instance? By God's grace it failed. Krishna! Did Pandavas forget the insult meted out by Droupadi in the Kuru assembly? According to the prevailing Dharma, they might have gone to forests at that time. But now what had happened to them? Are they not free now? If Kouravas refuse to give their due share in the kingdom, Is it not their duty to fight for their due share? Is it not their duty to chastise Kouravas while they are acting against Dharma. Krishna! tell Pandavas in my own words. I am happy here. Let them live as heroes but not as cowards." said Kunti.
Then Krishna requested all the elders who followed him upto the apartment of Kunti to stop. He requested Karna to give him send off upto the outskirts of the city and stretched his hand towards Karna. Karna holding the hand of Krishna boarded his chariot. Karna's chariot followed the chariot of Krishna. Krishna's chariot left Hastinapura.
Then Dhrutarashtra returned back to his assembly and discussed the events that had happened. Bheeshma said:
"O King! have you heard what Kunti said. We are very much astonished on hearing those words. Krishna also supported her. We do not know what will happen!" said Bheeshma. Then Bheeshma and Drona addressed Suyodhana:
"Suyodhana! It is not too late. Immediately proceed to Upaplaavyam and meet your eldler brother Dharmaja. Or meet Sri Krishna on the way and settle the matter amicably. You know we are at the threshold of our last days. At this late age, why you are forcing us to enter war field. We told what all we can tell. Then it is your will and pleasure. We are leaving." So saying Bhishma and Drona left the assembly. Dhrutarashtra also retired to his apartment.
Sri Krishna along with Karna left Hastina pura and travelled for a distance. At a place where there were none, Krishna stopped his chariot and alighted the chariot along with Karna.
"Karna! I know you respect elders. Kindly listen to me carefully. While Kunti was virgin, you were born to her through Sun God, by chanting the Mantra initiated by Saint Doorvasa. Hence you are the son of Kunti and eldest of Pandavas. If Dharmaja knows about this, he will prostrate before you. He will enthrone you. You wil become the King and Emperor of the entire Kuru kingdom. While you are coming on a chariot, Yudhishtira will stand by your side with a vinjaamaram (fan like object). Bheema will hold the umbrella. Arjuna will be your charioteer. Kings of Panchala, Yadava and other kingdoms will accompany you. Abhimanyu and others will be by your side. . You will enjoy royal pleasures like Mahendra and rule the entire Universe. There is one more gift for you. Along with her five husbands, Droupadi will accept you as her sixth husband. It is true" said Krishna secretely only for the ears of Karna.
(In this context it is pertinent to note what has been written in the original texts. Because, everybody will doubt how Sri Krishna, a man of such an eminent stature, will speak in such a manner about Droupadi.
In Sanskrit text written by Vyasa it was written thus:
"shashTE chatvaam tathaa kaalE droupadyupagamishyati".
In Telugu Maha Bharata written by Tikkana it was written thus:
'Paancaala raaja putriyu samchitamuga
ninnu pondu naarava varusan"

Here, there are two words, "pondu", "varasa".
The meanings of these words are flexible.
There is a famous play in Telugu "Paandavodyogamu" written by Tirupati Venkata kavulu. It was enacted, by eminent artistes, in Andhra Pradesh and many parts of the country and world at large, thousands of times.
In that play, it was written like this.
"ninna sati penDli yaaDu naarava bhartaga soorya nandanaa"
the words "pendli" (marriage), and "bharta" (husband) are heard only in this play and no where else.

Therefore, in my view, it may not be the intention of Sri Krishna that Droupadi will marry Karna as her sixth husband. What he meant might be that Droupadi will be in the marriageable order (Devar). If we take the meaning of the above words like this, it will not affect the high stature of Sri Krishna.).
On hearing the words of Sri Krishna patiently, Karna replied thus: "Krishna! I also heard about my birth secret long back. Kunti delivered me while she was virgin and left me in the river mercilessly. One soota brought me up and gave me life along with his sons, equivalently. His wife also showered her love and affection upon me by giving her breast as if I was her own son. As all the rituals, to be performed in Soota community, were performed by Soota and his wife. I also married a Soota girl as my wife. You have just now told that I will always respect elders and act according to Dharma. Therefore, I am bound to discharge my duties as a dutiful son to my Soota father and mother. Forgetting all these things, If I proclaim now, suddenly, that i am a Kshatriya and approach Pandavas, will it be called Dharma and justice? Tell me. I got number of relations, brothers, friends in Soota community. How can I leave them suddenly. Besides all these things, Suyodhana, without considering me as Soota, honoured my vigour and valour, and enthroned me as a King for Anga Kingdom and he is more affectionate towards me than all his 99 brothers. When we are at the threshold of war, how I can leave him mercilessly? Will it be proper on my part? Moreover, Suyodhana is more confident that I am more powerful than Arjuna. How can I betray him? If I join Pandavas and do not fight with Arjuna, the entire world will laugh at me and Arjuna. Does it not amount to insult to Arjuna?
Krishna! you told me what you meant. Kindly keep it in your heart and dont reveal these facts to outside world. If Yudhishtira knows that I am his elder brother, he will refuse to be the King of Kuru Dynasty. In my view, Dharmaja is the proper person to rule the entire earth. Dharmaja is performing Dharma Yajna. All the four brothers are Ritviks.You are their chief. Pandavas will kill Kouravas and burn them in the Sacred fire. We all will be killed in that Dharma Yajna to be performed in kuruskhetra which is a Dharma Kshetra and we will attain higher paths." said Karna.
"Karna! you are not paying heed to my words. You bear grudge and jealousy on Arjuna. Either you will be defeated or killed at the hands of Arjuna. You will never win Arjuna. Pandavas will triumph. You go back to Hastinapura and tell Bheeshma and others to fix a date for war." said Krishna.
"Krishna! what you predict is correct. Hence I refuse to join Pandavas. Along with me, Sakuni and Dussaasana are the root cause for this war. If they also join Pandavas, I will certainly join. As that is not possible, this is also impossible. If I win the war, I will see you back. Otherwise, I will meet you in heaven. Permit me to leave." said Karna and left that place on his chariot. Krishna also left Hastina for Upaplaavyam.
At that time, Vidura went to the apartment of Kunti. "Kunti! War is imminent to destroy the entire Kuru Dynasti. Nobody cared for the words of Krishna. Nobody tried to stop war. We do not know what will happen" said Vidura. Kunti kept quiet. Vidura went back to his apartment.
But Kunti was with a wavering mind. "Is it Dharma to kill ones own kith and kin for the sake of kingdom and royal pleasures? Waging war is nothing but acquiring sorrow. How can it be a pleasure and free from troubles. Karna will always be burning with jealous and anger. If I approach Karna and tell him his birth secret and sow seeds of love and affection in his mind towards Pandavas, what will happen. Will Karna give up war? Any how I should meet Karna." thought Kunti.
Kunti went to Karna while Karna was performing morning rituals on the banks of river Ganges. Karna saw Kunti sitting there at a distance. Karna went near her, told his name and Gotra and introduced himself to Kunti.
"May I know the purpose for which you have come here" asked Karna.
"Karna! you are the son of a Soota. You were not born in Soota community. Prior to my marriage, while I was staying in the house of Kunti Bhoja, God Surya appeared before me and blessed me with a male child. You were born to me. As per the existing Dharma, you are also the son of King Pandu and you are Kshatriya. You need not serve others like Soota. You are the eldest of all. You are the king and emperor of this Kuru Dynasty. Rule the entire universe. You need not remain as Radheya any more." said Kunti.
At that time, an invisible voice came from Lord Surya echoing "It is true."
On hearing all this, Karna said:
"What you said is true. I believe it. Kindly listen to my words also. Since my birth, on account of you, I was denied with all the Kshatriya rituals. Now is it proper for you to say that I am Kshatriya and I am your son. I was born to you through Sun god. But that fact was kept in darkness. How can I bring it to light now? While Arjuna was getting name and fame as a great warrior, if I join them now, people will think that I joined Pandavas having afraid of Arjuna. King Suyodhana enthroned me as King of Anga kingdom. Now, how can I leave him while the war is imminent. I am living at the mercy of Suyodhana. I cannot betray him. If I do so, the entire Kshatriya community will curse me. Therefore, I will fight with Pandavas for the sake of Suyodhana. But one thing is certain. I will never kill Dharmaja, Bheema, Nakula and Sahadeva and I will never leave Arjuna without killing him. Even if I am killed, you will have five sons. Even otherwise, you will have five sons, including me. You will never have six sons." said Karna.
"Karna! Nobody will decide the fate. I will agree for your proposal. You can kill Arjuna but leave the rest." said Kunti and left that place.
Sri Krishna arrived at Upaplaavyam. Yudhishtira and others received Sri Krishna at the outskirts and brought him to their palace. Sri Krishna told Yudhishtira "Suyodhana and others are deaf and blind. They did not heed my words. War is certain. I will narrate in detail what had happened in Kuru assembly, later" so saying Krishna went to his apartment.
On that night, Sri Krishna went to Dharmaja. "Dharmaja! I addressed Dhrutarashtra in a very friendly manner. But Suyodhana paid a deaf ear and heckled me. I need not repeat them as it is of no use. Dhrutarashtra tried his level best to convince his son Suyodhana but in vain. I also addressed the Kuru assembly about King Santana, birth of Dhrutarashtra, expansion of Kuru Kingdom by your father, King Pandu, yours' performing of Rajasooya Yaga, playing of wicked dice game and your exile to forests and your woes in the forests, all in detail. I also said that if your due share in the kingdom is not given, there will be total disaster of Kuru Vamsa. Other elders, sages and saints assembled there, also pleaded for an amicable settlement. Suyodhana left the assembly along with his followers. Dhrutarashtra called for Gandhari. Gandhari also chastised Suyodhana. But Suyodhana never heed her words. I also spoke some harsh words in anger but later remained peaceful. Suyodhana tried to manhandle me. I exhibited some miracles. Yudhishtira, I tried my level best for a peaceful settlement. But all my efforts are of no use. Now the war is certain. You can do as you like" said Sri Krishna.
"You all have heard what Krishna said. Make preparations for war." said Yudhishtira to his brothers.
"Krishna! you know much better than us. Please decide the future course of action. We all abide by your decision" said Dharmaja.
"Yudhishtira! It is not only my word, but the word of your mother Kunti also. She also told me to convey that the immediate task before you is war." said Krishna.
"Not only Sri Krishna but our mother also decided to wage war. Now we need not discuss about Dharma and Adharma. With the words of our mother, Kunti, all our doubts are dispelled. Let us proceed with war" said Arjuna.
"Krishna! we are having seven akshouhini army. Who will head that army, we have to find out. An eminent personality, who is equivalent to Bhishma, should be our Chief of Army. Find out such a personality" said Dharmaja.

MAHA BHARAT – UDYOGA PARVA – Chapter 4Part 1
FOURTH CHAPTER (INPART).