The outpost liaison is an emissary from your home civilization. If your liaison dies, you will never get a replacement, so protect him well if you rely on the caravan for a source of something that you request.
As your fortress increases in rank, the liaison's name will change accordingly - for example, a Metropolis will receive a Metropolis Liaison with the Dwarven caravan. When the King arrives with his entourage and you become a Mountainhome, your liaison will arrive as the royal Advisor and become a permanent member of your fortress, no longer performing his previous duties; if the King arrives due to the discovery of raw adamantine, you will still no longer receive a liaison, even though he may still be at the former mountainhomes.
The liaison arrives along with the Dwarven caravan, though not at the same location on the map.
 Arrival and Departure
The entry point on the map for the liaison is determined before that of the caravan wagons. This can result in the liaison taking a different route to your fortress than the rest of the caravan if the route chosen is not suitable for wagons; the wagons will then enter from a different spot. This means the diplomat has to travel unprotected but this is really the only downside to forcing the wagons to use one particular route. The liaison will then also leave without the caravan once the meeting is done. Providing your own armed escort for the liaison is not a bad plan.
The liaison will speak with the highest ranking noble in your fort, one of:
If the liaison decides to meet with your Expedition Leader or Mayor, make sure to turn off all of his labors along with the "dwarves all harvest" insane if prevented from leaving; this can happen after as little as two months of game time.rder, because your leader will tend to walk away from the meeting, making it take far too long to complete. A particularly impatient liaison may decide to give up and leave without completing the meeting, displaying the message "Diplomacy Stymied - A diplomat has left unhappy". A liaison can also go
If your leader is dead, there is nothing you can do but hope that a new one is elected before the liaison arrives or he/she will leave without a meeting. If the leader is too injured to hold a meeting, then you must arrange for them to have an unfortunate accident in time for a new one to be elected and hold a meeting.
If you are desperate to complete a meeting, consider locking the door on the meeting room until the meeting is complete. You don't even have to catch both in the office, the liaison is so keen on his bureaucracy, he will happily shout through the door, or even a thin wall. A sleeping dwarf leader can be woken up by deconstructing his bed. Lastly, an easy way to force the leader into the meeting room is to draft him (this can cause an unhappy thought if he has no military skills) and station him in the meeting room. Undrafting him may or may not be necessary to force the meeting to start.
The meeting can take place independent of trading sessions - although the liaison and traders arrive together, they are not tied in any other way.
The meeting consists of 8 screens with breaks, the breaks giving your leader a welcome opportunity to walk away from the meeting. Don't think you are done until the liaison confirms it and says farewell!
Conducting a meeting in a public place can generate an unhappy thought. Conducting a meeting in the leader's private office can generate a happy thought based on the quality of the room.
Oddly enough, liaisons don't need to eat, drink or sleep.