Fallout 4 created by Bethesda Game Studios.
Images used for educational purposes only.

Prerequisites: Complete Fire Support
Trigger: Speak to Paladin Danse
Reward: Righteous Authority, 50 Fusion Cells, 401 XP

- After saving the Brotherhood of Steel dudes outside the Cambridge Police Department, step inside. You can pick around the building to find a ton of basic supplies, as well as an Expert safe in one of the left rooms from the entrance (mainly ammo inside), the Holo Tape Operation Winter’s End in one of the equipment rooms (check the shelves in the room full of file folders), and Scibe Haylen’s Personal Logs in the first room to the right of the entrance. Explore thoroughly - everything’s free!

- Talk to Paladin Danse in the lobby of the Police Station when you’re ready to go, then follow him back out into the world. Tag Danse as he proceeds west across the world map and he’ll lead you to a cluster of Raider Scum; let him take point while you fire from the rear. (He’s really good at absorbing damage for you.) He’ll lead you through an ambush of Bloatflies, near the freeway over the road, and then another ambush, this one of Mongrels, beneath the freeway. No big deal. You’ll arrive at your destination in short order.

ArcJet Systems in Fallout 4.
Prepare for the easiest escort mission ever.
ArcJet Systems

- There’s nothing to see outside, so pop in the front door. You’ll wind up in the lobby. It’s pretty ramshackle - but for once if you check the nearby Nuka Cola machine you’ll find a filled bottle, this with Nuka Cola Quantum

- Follow Danse through the building until he commands your attention in a room full of robots. Check the wreckage for some more valuable tech stuff, then check the nearby terminal for more info on the history of this dump. 

- Continue following Danse and he’ll tell you to get a nearby door open while he runs recon on the next room. Check to your right for a terminal that will give you a terminal password. You can use this on the next, lit terminal on your right - though doing so will bring a bunch of Synths, robot-human hybrids, down on your head. This leads to a two-room-and-a-corridor firefight against the things, though don’t worry too much, ‘cause Danse will exterminate them all with extreme prejudice. Like, extreme.

- Check the rooms along the way as you follow Danse out of this room and into the next, larger area, where there may or may not be some Synths left, depending on Danse’s aim. Aside from some Workbenches on the second floor and assorted junk in the many rooms ahead, there’s not much to see. Danse really doesn’t need your help, so, uh, just kinda follow him and don’t get in his way.

I know these are the end times and all,
but, come on. Gross.
- There’s a couch in the women’s restroom! That’s unhygienic.

- There are a bunch of kinda useless offices along this route, the only one of which that’s kinda useful is down from the bathrooms. Inside you can find nine Missiles. Also near here are stairs that will lead you to one of the front offices; you can pop open an Advanced safe near the front terminal for some loot. Pretty solid. If you lost Danse - a real possibility - you’ll find him down the ramp from this room. He’ll lead you to the ArcJet Engine Core, at the bottom of which he’ll finally let you wander off on your own. Thanks, dad.

- Head through the narrow series of rooms leading off of the bottom of the Core. There's a Junk Jet sitting in the first room, and, yes, this is actually a weapon. Sitting beside it is the Technician's Personal Log Holotape.

- In the next room back you’ll find a Novice locked box containing… well, nothing good, really. There’s also a Fusion Core in this small room, and in the rear a Novice terminal that you can hack. Get through and you can activate the auxiliary generators. Doing this will bring a horde of Synths into the engine room to attack Danse. Run into the previous room and hit the red button on the control panel to activate the engines; this will wipe out the Synths. (Danse is fine, don’t worry. You can check on him if you like.)

- The nearby elevator on the bottom floor will now be active. Hop in and ride it to the third floor, then keep following Danse. He’ll lead you into a control room populated by more Synths. Help him wipe them out, then check the bodies for the usual swag - as well as the Deep Range Transmitter you came here for in the first place. (It’ll probably be on one of the bodies on the upper level.) That done, hop into the elevator at the opposite end of the room (make sure to check the medkit by the elevator for more items) to return to the surface.

- Talk to Danse before you leave the area. He’ll thank you for your assistance and hand over a fancy new laser rifle, Righteous Authority, which is already tricked out with a ton of mods. Oooo. He’ll also offer you membership in the Brotherhood of Steel, and if you accept you’ll unlock another new mission, Semper Invicta. (FYI, Preston won’t be happy if you accept, so you may want to ditch him before speaking to Danse. Assuming that makes a difference.)