In the Skyhold Tavern, you'll find Sutherland. There's a series of War Table operations in which you elevate Sutherland and his friends to being adventurers similar to the player character. After an operation is complete, check-in with Sutherland to unlock the next operation.
Be sure to complete "New to the Crew: A Young Hopeful" with Cullen and encourage Sutherland to hold onto the gear afterwards.
For "A Test of Mettle and the Crew", complete it with Leliana.
After the "A Crew of Adventurers" operation, you'll learn from Sutherland's squire that the crew needs help; this unlocks the "Sutherland and Company Missing" operation. Completing the operation unlocks the same-named quest on the Stormcoast.
Saving the crew at the Stormcoast will unlock one final operation associated with Sutherland (and thus a final dialogue with Sutherland).
1:02 -- Rat Delivers the Request for Aid
2:41 -- Stormcoast Battle
4:46 -- Thank You Dialogue
thank you, i wanted to know how it ended, the basterds went and died on me when I went to the Storm Coast and Bulls mission triggered instead