The lights are on
If you go to Tenpenny Tower, you will notice that one of the residents is Herbert "Daring" Dashwood and if you talk to him, he will ask you to go to the city of Rockopolis and find Argyle if you do go, you will see that he is dead on the ground, probably after the last episode on GNR and he couldn't escape like Herbert did. Go back and tell him the news and he will seem upset and he will give you the key to his safe which has caps and more for you to take but, don't take all of the caps as he will become hostile at you and will flee from you.
I saw a youtube vid about that but argyle was alive (probably a computer version). I finaly found rockopolis and found him dead. I had completed the tempeny tower quest let the ghouls in peacfully, but couldn't find dashwood afterwards, so I was very dissapointed. :(