Forum:Rex is gone

I got to the part of the Kings questline where I was supposed to pick up Rex. I had Ed-E in my party, so I did not bring Rex along with me. Now that I have gotten around to doing it, since Ed-E is being repaired by the BoS, Rex and the King are nowhere to be found. I've waited about 36 hours in various increments hoping they would return to the room, but they won't. Any ideas on where to locate either of them so I can finish this quest?