The Combat Zone (quest)

The Combat Zone is a miscellaneous quest in Fallout 4.

Detailed walkthrough
The entirety of this quest takes place within the Combat Zone as soon as the doors are opened, which some raiders will be defending in a small camp on the outside.

The Sole Survivor will first enter a foyer with two bound raider "rulebreakers" taunting them from the cashier's cage. There is an advanced terminal which unlocks the cage door, however these raiders cannot be freed, and interacting with them causes them to insult the player character repeatedly. There is an expert safe and some loot in the cage. Upon entering the main room, the Sole Survivor will come upon the end of a cage fight in progress with Cait and an unnamed raider, as Tommy Lonegan provides commentary while several raiders look on. If the Sole Survivor remains hidden, Cait will kill her opponent (which will grant the player character XP) after which Tommy taunts the Sole Survivor to reveal themselves. When moving further into the theater, the raiders will instantly become hostile and attack the player characters. There are four raiders, three raider scum, two raider psychos and one raider waster in total.

After clearing the area, the Sole Survivor will find Cait and Tommy hiding inside of the cage on stage for their protection. After approaching Tommy, he will be both grateful and enraged that his only form of clientele have been butchered before his eyes, commenting that he wonders if he should thank the Sole Survivor or have his "little bird" disembowel them in front of him. After a brief talk, he realizes that Cait is a liability (and an addict), and insists that the Sole Survivor take her from him until he can straighten things out and eke out a better life for them both. He also awards the player character the purse of the last fight, completing the quest. Speaking to Cait will allow the Sole Survivor to recruit her as a permanent companion.