I'd certainly suspect it more likely that he's a reprogrammed Railroad Synth, which is another example (with the Raider boss) that the reprogramming can have unexpected results.....but I left in the possibility that he was replaced since he has been in conditions (part of small, group, easily separated) where capturing him via teleporting Courser and replacement seems possible as well.

Danse has plenty of approval for siding with ghouls, he hates if you kill innocent ghouls and lie to them like Trish. He likes it for you to help Billy the ghoul reunite with his parent, and hate if you didn't help. After his quest, he gives you approval for speaking about synth's rights at the Bunker's Hills. He has a distaste for how the covenant torture synths. Maybe you didn't bring him around enough because he has plenty of moment where he likes for you to help ghouls.

I have a question - where exactly is this info about Danse being M7-97 coming from? Was that in Quinlan's message?

Because all I remember is an entry on synths still at large on one of the SRB terminals, and that one mentions a synth present at Boston Airport whose re-acquisition was considered too dangerous due to BoS presence, but the designation was different, iirc. Is there another synth there that we never really learn of?

The Institute didn't know him. All the replaced Institute synths know who they are and the Institute keeps track of them. He's from Rivet City where escaped synths are found, he's not an Institue synth but a mistake made by the RR who supposed to help synth decide to give him a crappy childhood where he has no parents, no siblings, no one to care and love him, and people wonder why certain synths turn out to be raiders under the RR's commands.

I've had the discussion here on the Forum, that the Railroad should be held responsible for their reprogrammed Synths who turn to the 'dark side', the Pro-Synth refrain seems to depend on humans can be killers and that its like blaming the parents of a human.

My point was always that reprogramming a machine brain you have only limited knowledge off, by a Doctor who isn't in any way an expert in the field of android brains using a machine that isn't designed for the purpose is always going to lead to some of those reprogrammed being failures, leading to damaged individuals. So why wouldn't the RR be responsible for the deaths that follow?

Blind Betrayal starts after the BoS has had access to the Network Scanner from Molecular Relay.

Depending on who built the relay, either Tinker Tom, Sturges, or Proctor Ingram handed it to the sole survivor and he ran a network scan. If the BoS gets a copy of it (which Sturges, at least, will gladly make them a copy with no fuss at the Survivor's request), they will start trying to anolyze it (Quinlan being the party responsible). It will take some time (typically the time it takes to complete Liberty Reprimed) and then Quinlan will crack the encryption on the copied data from the Institute mainframe.

On it will be multiple lists and databases. One is a list of all missing synths. In that list is M7-97, an apparent photograph of Danse, and a full copy of his DNA genome. The Brotherhood keeps the same data on file (ostensibly for identifying casualties, I'd assume -- but that's just guessing), and ran a comparison and it was a virtually identical match. With DNA evidence, they were convinced that Danse was a synth.

Danse compounds the problem by going AWOL when Haylen warns him. He even admits that he made it worse when you ask him about it. Instead of there being any chance of him giving his side of the story to Maxson directly, Maxson is convinced that this shows that Danse was an infiltrator (instead of an unknowing dupe), and orders the immediate execution.

If you have X6-88 with you when the truth is revealed, he'll state afterwards that he didn't know that Danse was a synth. Taking him at his word, that means an SRB Courser had no clue and a BoS plant would be one of their most important assets.

One of several reasons I'm equally convinced that Danse is a Railroad refugee.

So will we see "The Legend of Danse" as story DLC? lol

Yeah, I've played through Blind Betrayal, I'm just asking where in the game itself is it stated that Danse is M7-97, specifically. I'm not saying it's not true, I just don't remember ever reading or hearing anything except Kells' message to Maxson about Quinlan's discovery, but that didn't give many details.

I just always thought https://40.media.tumblr.com/e4c8b1c2f86866488b2f82843f0f9504/tumblr_nysteynZ711u939ubo3_r1_1280.jpg SRB terminal entry was about Danse, but since that's a different designation I guess potentially someone else at the Airport is a synth?

I don't think you yourself actually see the entry on a terminal. The Network Scanner Holotape you plug into the Institute computers pulls a bunch of info, and once the data is cracked by Quinlan, he discovers Danse's picture and DNA in one of the files. He lets Maxon know, who turns to you and tells you to take care of it. You get sent to Quinlan for more information, and he says in dialogue that Danse is M7-97.

Ah, ok, thanks, that explains it. I must have not been listening to Quinlan too attentively.

Maybe I'm not understanding what you're asking, as I thought I already answered it.

When building the Molecular Relay and then using it, whomever helped you build it hands you the Network Scanner (a holotape). They then ask you insert it into any terminal in the Institute and run the program, which takes a snapshot of everything on the Institute Mainframe/Network. You bring it back and hand it in to the quest giver -- if that's not Ingram, you will be asked by the Brotherhood for a copy of the Scanner. The MM will make it for them with no issues, and the RR can be weaseled into it, I believe.

That network scan is how the BoS is going to get a copy of the database necessary to identity Danse as M7-97. You never read it on a terminal. It's an encrypted database that they crack off screen while you're off being the player character.

Yeah, we don't get to read it, hence why I'm asking where we, the player, get the name M7-97 from. That's all. Since swk3000 above says Quinlan tells us, I suppose I just forgot he said that, or didn't listen to him carefully enough.

I sided with the Railroad so I destroyed the BoS and Institute. But X6-88 is still friendly with me and is ready to travel. He's hanging out near the Libertalia. I don't remember killing Danse so I'm wondering if he wants to travel and where he might be at?

Yeah, Quinlan has the actual dialog. Perhaps I misunderstood over asking 'where?' instead of 'whom?'

No worries. Answer's available now.

"Blind Betrayal" is the quest. You receive it after getting quite a bit through the BoS questline. It's after "Liberty Reprimed", I believe. So, unlike other companion quests, it is linked to a faction quest line and not the companion's affinity level.