The plot of Heroes of Might and Magic V.

Hello.

1. Where can I find the missing plot scenes about what happened after the Alliance defeated Kha-Belek in the original game – when they went to the Silver Cities of the Mages?
2. How did the plot of Heroes of Might and Magic V end, with the victory over Biara? Where can I find the continuation?
3. Where did Railag disappear to? What are Heroes of Might and Magic 1.1, 5.5, 3.x??? Are these like patches? And which patch is the latest? And where can I download additional campaigns for Heroes 5?

Thank you to everyone who answers.

I can only partially answer the second question. There is also Dark Messiah, which tells about the very son of Kha-Behekh. The events take place approximately 20 years after the campaign of Heroes of Might and Magic V. There is a separate game dedicated to him, which is called that, but there is also a scenario in the Heroes of Might and Magic V itself about him. The scenario is located in the Lords of the Horde in the binDM folder; it briefly retells the plot of Dark Messiah.
I don't know the answer to the other questions; maybe someone will help. Simply, all subsequent parts tell about events that happened much earlier in Ashan.