Birds of a Feather

 is a quest in Fallout: New Vegas.

Quick walkthrough
This quest can be activated after completing several jobs for the Van Graffs in Freeside. To start it talk to Glory inside being the counter. She will say Jean-Baptiste has a job for you. Speak to him and he will task you with bringing Rose of Sharon Cassidy to him.

She will be down at Mojave Outpost unless you have already gotten her as a companion via another quest. When you bring her back to him he will reveal his purpose is to kill her. From here you can choose to let him kill her, or become hostile by saying "Shoot her and you'll be sorry" If you choose this method you will have to kill all the guards inside the Silver Shop. Alternatively you can let her die and you will be payed a large sum of caps.

Detailed walkthrough
1. First you will have to guard the front door. A series of NPC's will come up to you, and you must remember to allow no drunks and everyone must be searched before going in. Passing a speech check results in being paid a bonus on top of the job's normal pay.

2. You will need to deliver a package to a man a bit east of New Vegas. With a high speech check you can get 200 caps from the man.

3. You will need to bring back Rose of Sharon Cassidy to the Silver Rush to be killed. If you accept, you will lose her as a companion and subsequently fail her companion quest; however you will succeed at this quest and get a large sum of caps as a reward.

You can also choose to resist her death. This results in a fairly difficult gunfight, especially if you're low level. Numerous guards, and one will either pick up or already equip a plasma caster, which will do tremendous amounts of damage to you. If you isolate Jean-Baptiste you can focus him down first, but he has very high DT. All the guards and his sister do not have as much, so if you need to kill the guards and his sister before moving on to him. Doing this will result in you failing this quest and no EXP reward, however, you will be able to complete Cassidy's quest for that reward. Or, you could complete her quest first and then lead her here to her death and complete both.