Heartache by the Number

 is a quest in Fallout: New Vegas.

Quick walkthrough
Talk to Alice Mclafferty in the Crimson Caravan Main Office, ask for work. After telling you there's no caravan work she'll ask you to deliver a holotape to Doctor Thomas Hilderm. He can be found inside the Terminal at Camp McCarran, just east of New Vegas. He will you to return to Alice, & also to investigate Vault 22, which will start the quest "There Stands the Grass".

1. Cass is drowning her sorrows at the Mojave Outpost. Her advice? Go work for the Crimson Caravan. 2. Pitch in at the Crimson Caravan company if you're looking for caravan work. 3. Return to Cass and see if you can get her to part with the title for Cassidy Caravans. 4. Pay your respects with Cass at her caravan's grave. 5. Investigate the wreckage of the Griffin Wares caravan with Cass. 6. Track down Durable Dann's missing caravan with Cass. 7. Investigate the Crimson Caravan for reasons behind the attack. 8. Investigate the Silver Rush in Freeside for evidence on the Van Graffs' guilt. 9. Take the evidence of the Caravan attacks to Jackson at the Mojave Outpost. When the questline is completed, Cass will receive the perk xx (something giving health).

Behind the Scenes
The name of this quest is a reference to a song called Heartaches by the Numbers.