I'll share.One of my PCs has in their background that they are from an elven clan whose women were all taken as slaves. He and his brothers had made it their mission to find them.
He has been meeting a "deep throat" throughout Adventure 1 Zeitgeist who has information on the slave trade. Right now they are chasing down one of these leads, which happens to be the home town of another PC, whose father went crazy when she was a teenager while he tried to create the anti-life potion. They end up finding out that a scientist has been buying elven women as slaves and experimenting with old notes of the other PCs father. As a matter of fact because the other PC is an aasimar, the mad scientist is a distant relative her father sired after he went crazy and left home.
I chalked a third PC's background in the mix because her father and brother are pirates and may apart of hte slave trade. The pcs found a ship with the manifest of part of the fleet, and her last name was on there twice.
In a nutshell, the PCs investigate slave trade, stumble upon zombie epidemic, chase down rogue pirates, find themselves in "The Thing" movie.
Adventures I am using
Mansion of Deceit by Blackbyrne Publishing - this sets the basic frame of the adventure.
A 4th edition D&D insider Zombie Siege - I found the ending to deceit to be anti climatic, so I wiped it and installed this zombie siege replacing the orb with the PC's father's book. Essentialy the mad scientist accidently created an undead army.
Custom Ship to Ship Combat Rules - The PCs find evidence of where the slave ships come and go and track them down. I spent a week creating ship to ship combat rules that could be used for any ship to ship encounter. I find the current rules to only cater to a couple of PCs and not try to incorporated everyone. It uses 4e Skill challenges.
Cold Visitor by LPJ Design - The captain is long gone, but if tracked leads to an island "like Axis Island" controlled by the Ber. Everything else is like the adventure except they are not on another plane persay. Created a skill challenge combat for the end of this one and inserted a Capture the Flag encounter from Kobold 13.