Left My Heart

 is a quest in Fallout: New Vegas.

Quick walkthrough
Go to Cottonwood Cove and speak to Mrs. Weatherly inside of the slave pen.

Talk to Canyon Runner to obtain the key for the Weathers.

Talk to one of the Weathers and set them free.

Detailed walkthrough
1. Travel to Cottonwood Cove and speak to Canyon Runner near the slave cage.

2. Inquire about the slaves and then talk to Mrs. Weathers inside the cage.

3. Find Canyon Runner and inquire about purchasing the slaves.

4. Pay 300 Caps outright or pass the speech check (Requires 50 speech) to pay 150 Caps.

5. Enter the cage with the Weathers Slave Key and talk to any of the Weathers to set them free.

Alternately, if you are on bad terms with the Legion, you can simply kill the guards, pick the lock/take the Weathers Slave Key and talk to them to set them free. Their collars can either be disarmed either using an Explosives check (50?), or using the key.