The group has come to a city of which half has been taken over by orcs. The humans still control the other half. This stalemate has lasted for approximately 2 weeks with occasional border penetrations by each side into the opposing half (guerilla raids, party loves 'em, 2sp/head!).
But things have changed for the better/worse. An army from the north, in an attempt to make good on the city/kingdom's problems, has sailed into town. They wiped out the mercenaries guild (the only opposing force) and stated that all people were now citizens of the new empire and they would be rid of the orc menace within two weeks. Everyone has been drafted into the militia. What is really bizarre about the army is that it consists of all sorts of races (human, elf, 1/2 elf, etc), all speak a common tongue, they are VERY well organized yet are individuals. (Everyone has personal weapons, armor, etc.)
The party can decide what to do. They may not like the idea of being drafted into the militia to be used as fodder (for an empire they don't belong to) to rid the town (that they are only visiting) of the menace. However, it WILL provide for some good roleplaying trying to explain to the new invaders why the group should (or rather wants) to remain together.
The plus is that after the orcs are gone, the militia wil be disbanded (or so the invaders say) and the members will be free to go on their way as citizens of the new empire (more lands to visit). The other bonus is that the party may be able to get ahold of a little of the recaptured territory.