From the introduction:
I started out with the ambition of changing the 4th Edition adventure series H1: Keep on the Shadowfell, H2: Thunderspire Labyrinths, and H3: Pyramid of Shadows – as there was very little in the plotline that really tied these adventures together into a full story.
Having just finished up the conversion of H3 one year have gone past and I have come to realize with the later releases of P2 to E3 that the strong Orcus plotline that I was looking for is actually being deliver by Wizard of the Coast. We are now facing a mega adventure path from level 1 to 30 circling around Orcus the Demon Prince of Undeath – and I am loving it. Thank you very much WoC, this is going to be a great saga to be told by my players.
However there are still some small adjustments that can be made in order to tie the adventures together more, at least in P1 to P3. I therefore decided to continue trying to enhance these great adventures to the best of my ability.
Please note that you should read through the H1 and H3 Conversion Guides first, as it gives you the full background story to the campaign.