The Calcutta Chromosome

I'm sorry. What? 

Not sure I completely get what Antar's role is. Is he the new Laachan? Is he the Ronald Ross of his time? How on earth do these people not age? I just am so confused and I don't understand anything at all, but I had a good time being confused as all hell.
But what was up with that imagined moment between Urmila and Murrugan?? I was totally getting vibes between Urmila and Sonali, so it felt so out of place.