Lou directs you to the thugs' usual hangout spot: Behind his barn. Six of them are there, having a chat as though no one would suspect a thing. "...An' for some reason," one of them is saying, "she wanted me to tell you lugs that she appreciates the job that we did for her on the Furlbrows. Gave me a pile o' gold to split with you all. None of it counts towards extras, though. You can ask her for that, if you care about gettin' paid for takin' out Lou." He scoffs under his breath.
Lure the thugs off the farm. Just blow them up. Warn Lou that his life is in danger right now. You can get rid the thugs later.