|Grouse - Desolation’s Edge||Cash, Rare Gun||31|
You’ll be able to accept this mission from Grouse In the Wake of Doubt after you’ve completed the Main Mission The First Vault Hunter.
Take energy trap / Go to Temple
Once you’ve accepted the mission, collect the energy trap from the table and then head over to the waypoint on the map to go the temple.
Place energy trap / Fill energy trap with spirits: 0/6
After you’ve entered the temple, place the energy trap down on the marked area and kill any enemies that spawn within the marked location to fill the trap up with six spirits.
Destroy cyclone / Get stabilizer
With the Energy Trap filled up with spirits, collect it and head back out into the zone and take down a Cyclone, then collect the stablilizer from the floor.
Destroy outrunner / Get shock absorber
Now continue searching around the marked area to find an Outrunner and take it out to collect it’s Shock Absorber from the floor.
Return to research center / Place weapon parts 
Once you’ve collected all the items that Grouse desires, head back to In the Wake of Doubt and connect the weapon parts to the gun on the table.
Place energy trap / Back up!
After you’ve connected the pieces to the gun, head over to the left side of the table and place the Energy Trap. Wait a few seconds and back up over to the waypoint to progress to the next step.
Pick up cannon
The final thing to do for this mission is to pick up the cannon from the table and listen to the dialogue to complete the mission.