Left My Heart

 is a quest in Fallout: New Vegas.

Quick walkthrough
Go to Cottonwood Cove and speak to Mrs. Weathers 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 (50 speech) to pay only 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 Caesar's Legion:
 * You can simply kill the guards
 * Pick the lock or take the Weathers Slave Key, talk to the slaves, and set them free.
 * The slave collars can be disarmed either using an Explosives check (50), or using the key. If the collars are not disarmed, talking to Mrs. Weathers with a speech check of 50 causes them to run free, exploding on the way out.

Disarming the collars or not, you still complete the quest.

Note
There is a truck perched on a precipice at Cottonwood Overlook. If the lock is picked, a large number of radioactive waste barrels tumble out - killing everyone below. If the slaves have not been freed by this stage, the quest will be failed.