When you first meet Veronica, don't be rude about the Brotherhood of Steel.
To start the quest, you need to have 3 out of 9 unique conversations of Veronica at certain locations or after speaking with certain people for the first time.
Speaking with Tom Anderson's in Westside about his affiliation with the Followers and hearing him confess to murder during the White Wash will make Veronica pipe up about the Brotherhood's lack of a good cause.
Just outside Vault 3, Veronica talks about how the Fiends are giving the NCR hell.
Going to either Nelson or Cottonwood Cove makes her comment on how the Brotherhood is not on the Legion's radar.
At the Camp McCarran Terminal building, standing near the main or eastern set of double doors makes her comment on the number of NCR troops in the area.
Also in Camp McCarran Terminal building, the first time you meet Dr. Hildern and he says, "A pleasure to meet you!" Veronica talks about the NCR investing in new research.
At Nellis Air Force Base , listening to the tour at the Boomers museum makes her comment on the Boomers' and Brotherhood's aggressiveness.
In Old Mormon Fort, Julie Farkas's line, "Are you here to drop off medical supplies? ..." The phrase happens only the first time you meet her and Veronica admits she admires the Followers.
Before the end of Come Fly with Me, Jason Bright's line, "We wish to escape the barbarity of the wasteland..." when questioned about the "Great Journey" reminds Veronica of Father Elijah.
At the Silver Rush, meeting Gloria Van Graff for the first time and saying you're just browsing makes Veronica discuss energy weapons.
The only triggers that are available at any time are the Nellis museum, the Nelson/Cottonwood Cove, the Vault 3, and the McCarran door.
I used Nelson, McCarran doors, and Dr.Hildern.
Approaching Hidden Valley is easy if you have a Powder Ganger disguise. Veronica will get you inside the actual bunker which is on the west edge of the fence area composing Hidden Vally.
Meet the Elder and follower Veronica's instructions to a terminal in a shack in Helios One. Accessing the terminal makes her give suggestions for tech to retrieve.
To get the Pulse Gun, you need to have 100 lockpick or steal a key from a cabinet in Pearl's barracks and then get the gun from Vault 34.
The rangerfinder is owned by a little boy in Westside who is usually near the east gate. To work, you need to have completed That Lucky Old Sun by sending power to ARCHIMEDES II laser system.
The agriculture data is from the server room of Vault. Refer to my There Stands the Grass quest vid if you need some visuals of Vault 22.
With one of the items, return to the Elder just to see Veronica be disappointed.
The quest gets tricky here since you have to push for her to leave or stay with the Brotherhood.
Staying with the Brotherhood gives her the Bonds of Steel perk which increases her DT by 4. Endings associated with her staying involve depression or bracing herself for the genocide of the Brotherhood by the NCR.
Having her leave them leads to the Causeless Rebel perk that amps her unarmed attack rate and the associated ending(s) has her wandering the wasteland.
After a decision is made, you'll have to deal with some pissed Paladins when you exit Hidden Valley.
You can delay having to kill them or push them to be hostile. If they go hostile first, you can kill them without failing the quest.
After dealing or delaying them, follow your quest objectives until they are dealt with and the quest is complete.