Redshift Community

First of all, many thanks for making such an excellent game!
I have just completed the main quest (good ending).
My question is - how do I start Islands of Ice and Fire main quest?

Go to Mithria harbor and talk to captain Hanty. Select "Islands of Ice and Fire" as your travel destination. When you arrive talk to the guy in front of you.

(All expansions are accessible by traveling to them from one of the harbors. Low level ones are usually connected to Matras while higher level ones to Mithria.)