The situation:

When someone else has written the bulk of the story (and this is a 9 part episode serial type deal) and then you come in on just one of the episodes and write a good part of the dialogue and action (but the main setting and plot is still part of the original serial plot), then how do you properly get listed in the credit lines for what you've done? What wording would be used?  

For just that one episode, the credits would be:

Story by 'the other guy.'

Written by 'you' and 'the other guy.'


Phil