Andy and Charlie

 is an unmarked quest in Fallout: New Vegas.

Quick walkthrough

 * 1) Speak with Andy
 * 2) Head to Ranger Station Charlie
 * 3) Return to Andy

Detailed walkthrough
Former NCR Ranger Andy, will ask the courier to check on Ranger Station Charlie. Upon arrival at Ranger Station Charlie, you will find that all the rangers have been killed by legionaries, who left behind 2 holotapes, the first one located under the desk, and the second one right next to the desk. One major statement is that they captured a female Ranger, (the same female Ranger you have the option to fight in the arena at The Fort). They detail that Caesar's Legion is sending a message to the NCR.

Return to Andy with the news and he will give you 200 caps, plus an increase in reputation for both the NCR and Novac. There is also a speech check you can complete for 60 speech, which will net less reputation with NCR and Novac but 200 more caps.

By completion of this unmarked quest, Andy will give you a perk called Ranger Takedown. Alternatively, you can pass a level 30 speech check and he will teach you the move.