A Loose End is a quest that can be obtained within the Commonwealth, in Fallout 4..
It is expressed that the Brotherhood of Steel considers Virgil to be a threat, even after his help in infiltrating the Institute. Eliminate him, and prove the Sole Survivor's loyalty to the war effort.
- Lancer-Captain Kells will reveal that Virgil is considered a priority target for assassination, even after his help towards the BoS cause, and his death is a priority mission now for the Sole Survivor.
- Upon reaching the rocky cave, the Sole Survivor may choose from a myriad of options in how they want to deal with Virgil:
- Should Virgil already be dead, this quest can be immediately completed by informing Kells.
- The Sole Survivor may simply kill Virgil, which can be made relatively easier by curing him with the experimental serum. His turrets and protectron guardians must also be dealt with.
- Should the Sole Survivor lie to Virgil and tell him that the serum was destroyed, he can be convinced to go down without a fight, which also includes his guardians.
- The Sole Survivor may choose to lie for Virgil, in which he will remain in the rocky case.
- After reporting back to Lancer-Captain Kells, the Sole Survivor will be rewarded with a unique t-60c helm.