He asked you to get rid of "invisible monsters" living in the basemants. These are a group of NightKins. The journalist's character was pretty weak in combat (Strengh 3, low Gun skill). Moreover, he played on harcore mode, and the combats were rather tough. He was killed quickly by the leader of the Mutants. Then, he tried another way to deal with them : he sneaked and managed to reach their leader... who was friendly ! You could talk to him. The NightKin leader was quite insane : he talked to a buffalo skull which he workshipped as a god. Thanks to his high speech skill, the journalist managed to find a compromise : these Stealth-Boy addicted Nightkin believe the a pre-war shipment of their precious drug was to be find in the higher levels of the site.
The only problem is that the shipment is guarded by a ghoul sniper... who was friendly as well ! He would give info to the player if the later accepted to find a lady ghoul (he wanted to have six with her... urgh !) who was trapped in the basemant when the NightKin came. With little investigation, it came out that the poor lady ghoul was lying dead in a basemant's room, attached by the NightKin.
Thus, the ghoul sniper revealed that the Stealth Boy shipment never arrived in Repcon. When the NightKin leader knew about it, he got mad, but the high speech skill of the player managed to avoid the confrotnation. Finaly, the NightKin left the base. The cultist's human scientist congratulate the player about the news, but another issue appeared : the ghouls wanted the player to convice the human scientist that as a human, he could not survive in space.
Whan the player told the scientist that he was a human, the latter did not believe him. The lie was so anchored in his insane brain that the player had to give him an evidence. Which was in that case, his non-resistance to deadly radiations (the site is filed of those). The truth was unavoidable, and the scientist got even more crazy : in order to revenge, he wanted to fail the take-off and kill all the ghouls. Through a long an intense conversation, the player managed to calm down the scientist and save the ghouls.
Other tidbit : the journalist managed to solve the Primm Quest by disguising as one of the convicts.
Journalist's impressions
One important note : he's an absolute fan of the first two episodes, but hated the third one (gave it an overall mark of 4/10 if my memories are correct). Then, his point of view differs from the regular video game press, what is rather interesting.
While he played the four hour-long demo, he first believed and feared that New Vegas would be another copy of Fallout 3. Nevertheless, the more he played the game, the better it get. According to him, the game is very deep : the quests are well-written (better than FO1&2's !), the characters and dialogues are pretty good, and so is the music. The Repcon Quest was deep and complicated and could be solved in numerous ways. For instance, you could manage to set every group (cultists/Nightkin/ghoul sniper) against each other and end up in a general fight.
His conclusions are rather excellent : he's extremelly enthousiastic and impressed by the game.