the current party are well established and have numerous NPC contacts, their own personal goals and a few common enemies of various power (a criminal crime lord, a thieves guild leader, an assassins guild leader and an evil sorceror/leader of a dark cult. im resisting the 'long lost cousin' angle and am looking for a realistic reason for the new pc to join the party. the story arc is already rather complex so im aiming to keep any relationship/connection to the current lists of npcs simple.
two questions im deliberating over are:
1) why would the new character want to join the party? (motivation)
2) why would the party want him to join them?
i keep coming back to the common enemy/common ally angle. keep it simple.
thoughts?