Semper Invicta

Semper Invicta is a quest and achievement in Fallout 4.

Quick walkthrough

 * 1) Return to Cambridge police station.
 * 2) Speak to Paladin Danse.
 * 3) Support the Brotherhood recon team.

Detailed walkthrough
Once the Survivor complete the quest Call to Arms, this one will show up automatically, asking the player character to go back to Cambridge police station and talk with Danse.

After the discussion, Danse asks the Sole Survivor to help both Rhys and Haylen doing their respective job.
 * Cleansing the Commonwealth
 * Quartermastery

Once the job is done, the quest The Lost Patrol will begin.

Trivia
"Semper Invicta" means always invincible, or always victorious.