This quest requires you to build a chair for Mama Murphy in Sanctuary and bring her various chems as she taps to "The Sight" and give you visions of the future in return. There are 12 different visions but she'll only be able to tell you five of them, depending on the active quests, your progress in the main story, or your allegiance to various factions. Take note that after giving her Psycho and she gives you the fifth and last vision, she'll die from chem overdose. You can also prevent this from happening by refusing to give her any chems and passing Charisma speech checks.
The quest objectives are very straightforward:
Here are the possible visions she can give you:
(Source: Fallout 4 Wikia)
"Diamond City holds answers, but they're locked tight. You ask them what they know, but People's hearts are chained up with fear and suspicion. But you find it. You find that heart that's gonna Lead you to your boy. Oh, it's... it's bright. So bright against the dark alleys it walks. That's... that's what you need to do, kid. Follow the signs to the bright heart."
"You're looking for a man. He can help you, but he ain't gonna be the man you expect. He's somewhere... deep... and dark. Surrounded by folks with nothin' but cruel intentions. But there's... an echo... Something in the past that can help you. When you meet the fat man, and the angry woman, tell them to "remember the Quarry and Lilly June on the rocks", and they'll let you and your friend pass. "
"You're on the trail of the man who took your boy. I see a house. Locked up tight. Chains put on by a smiling shark. But there's another way. I can see it. A key. Lost and forgotten. Fallen down below. Search the chairs beneath the house. They hold the secret. "
"You walk into a house. The man who owns it has secrets. But he's no fool. He hides everything in a closet with no doors. But I see him, kid. He's sitting down. Brought out the red toolbox and the coffee. Then he reaches beneath where he's working, and the closet opens. "
"I can only see that you're on the right path. If you had any doubts in your mind, you shouldn't. The man you're after. He's the one. He wears all the pain he's caused like a shield. Be strong, kid. The Sight's getting... foggy... but your energy is glowing brighter than you know. You can win this. He can't hurt you anymore."
"You're walking into a sea, but it's not Water you're afraid of drownin' in. It's something... invisible... but... radiant... It burns everything in it, but... no... I can feel them. There's People. Calling out to something. Chanting. They can show you the way... but... they're so hard to read... Be careful around them, kid. "
I see you... the mighty hunter... only what you're hunting ain't an animal, or a man. It's something different. Maybe something more than human. But... what's this? I see a man in a white outfit. Standing over your prey. And he says something... it's hard to make out... But I'm tryin' kid... He says "Z2-47, initialize factory reset. Authorization code Zeta-5-3-Kilo"... Then he falls... And he's still...
I see you surrounded by outstretched hands. Everyone needs your help, kid. Everyone wants you to see things their way... And whether you want it or not... You're gonna have to decide which ways of life keep going in the Commonwealth... and which end...
You're wearing a lab coat. You're standing with... men of science. Visionaries. Brilliant but misunderstood. I see a land marked up, like a great experiment. Each test a new beginning. Each sacrifice an acceptable loss. You will not be loved, but you will save humanity. However you choose to define it.
You're standing with... the People. Working together. United. I see a land filled with hope again. Fear falls away as the brave step forward to join the ranks. You're a hero. A symbol for a better world. Our world.
You're wearing a suit of Steel and energy. You're standing with... your brothers. Your mission. Accomplished. I see a land secured, contained. Dangerous objects taken from those who don't understand. Those who can't be trusted. You are the uniform, and you wear it well. And your rank and chain of command protect you better than the thickest armor.
You're wearing a mask. You're standing with... outcasts. The underdogs. The lanterns in the dark. I see a world that will never know your sacrifice. You have led the enslaved to freedom, but they must still hide from those who don't understand. But you'll be there for them. You'll see their humanity when no one else will. You'll be their guardian in the shadows.