Blind Betrayal

Blind Betrayal is a quest and achievement/trophy in Fallout 4.

Quick walkthrough

 * 1) Speak to Elder Maxson
 * 2) Speak to Proctor Quinlan
 * 3) Follow Scribe Haylen
 * 4) Speak to Scribe Haylen
 * 5) Travel to Listening Post Bravo
 * 6) Locate Paladin Danse
 * 7) Speak to Paladin Danse
 * 8) Execute Paladin Danse
 * 9) Retrieve Paladin Danse's holotags
 * 10) Watch Danse's execution
 * 11) Speak to Elder Maxson
 * 12) Return to the Prydwen
 * 13) Speak to Elder Maxson

Detailed walkthrough
The Sole Survivor has been informed that Elder Maxson has an urgent mission and the Sole Survivor should report to him on the Prydwen immediately. Agree to his order. Using Charisma, there are a few possible choices to make him believe the player character (Medium).

The Sole Survivor needs to find Paladin Danse and sort out the confusing news they've heard about him. Danse has disappeared, but Proctor Quinlan (on the main deck) has a way to track him down. Then speak to Scribe Haylen for a more private conversation.

Head into the northern Commonwealth wilderness, and locate Listening Post Bravo. Avoid or neutralize the turrets, power up the elevator, and ride it down.

Watch out for a small Protectron presence. Paladin Danse is nearby, and there are multiple options to resolve this situation.

Plan A: The Last Danse
Remove him as a threat immediately, without talking to him, or speak to him, using a threatening tone. If the persuasion attempts fail, Paladin Danse gives an order. Oblige him, then retrieve Danse's holotags.

Return to the Prydwen, and inform Elder Maxson. The Sole Survivor receives the rank of Paladin.

Plan B: One Last Danse
Using charisma speak to him, with friendly answers. Refuse to remove him as a threat. When prompted, choose any persuasion attempt and succeed with it(Medium). Paladin Danse sees the way of thinking and hands over his dog tags.

Exit Listening Post Bravo, where the escape is interrupted. Answer Elder Maxson, the person responsible for the interruption. One can:
 * Agree to his way of thinking, and remove Paladin Danse as a threat.
 * Agree to his way of thinking, and watch as Paladin Danse is removed as a threat.
 * Disagree with his way of thinking, and convince him to let Danse live.

After a begrudging agreement, the Sole Survivor is left with Paladin Danse. One can:
 * tell him to stay (he remains here)
 * beckon him to accompany the Sole Survivor as a companion.

Whatever decision made, return to the Prydwen, inform Elder Maxson, and receive the rank of Paladin. The Sole Survivor will also be given all of Paladin Danse's items, including his living quarters and personal power armor.

Bugs

 * Once Elder Maxson arrives in the vertibird after exiting the listening post, he may start walking off into the distance making it very difficult to enter dialogue with him. One potential fix is to continually step in front of him and prevent him from moving too far away from Danse allowing Danse to be spared or executed by Maxson. If he does get away, the quest can be completed by executing Danse yourself and finding Maxson to the north and briefly talking to him to return him to his quarters.
 * Upon completion, Danse's power armor is found on the closest rack to your right when entering. But if the player character loads a quicksave directly after going onto the main deck the armor will disappear.