“ It is traditional for two warlike countries to each give their first-born royal prince as a hostage to each other to prevent war. One of the princes has been murdered, and the PCs have a few days to rescue the prince in the other country to save him from being executed and a bloodthirsty war from breaking out.”
“ Poison can only ever be the tool of a murderer - as such, alchemists are tightly regulated by the Crown, and anyone found in posession of an unknown substance is forced to taste it themselves.”
“ A secret MLM (pyramid) company that offers eternal life, but in fact it transfers the life forces of its members to those position 'above'. If you get high enough, (meaning you get enough new members) you start to enjoy the benefits. Maybe a willing sacrifice is much more effective for the transfer. But no one says, that a suddenly unwilling member, threatening to tell the authorities, may not loose it involuntarily... thus start people to vanish, and aged corpses are deposited somewhere safe.”