Here are some observations that might help in developing a story in UGC.
If you have some experience with such things, do add your post with your suggestion.
How to add a specialist crew member to an adventure.
>>> Trick 1 An NPC is whatever you tell the player it is.
You need a Interplanetary trans-space Volcanologist for your story.
np make a generic NPC dressed in uniform that spawns after you reach a certain point on the map.
have a trigger cause a bo to state one is needed, and one will beam down shortly.
Have another trigger on the walk path close by...you trigger it and
the expert 'beams' down.....spawns in writer terms
NPCs can be anything or anyone....use it to your best advantage.