Jewel of the Commonwealth

Your Fallout 4 walkthrough continues! Learn how to safely navigate the radioactive dangers of Forest Grove Marsh and the elevated highways of Mass Pike Interchange.

Alright, let's get this 'Jewel of the Commonwealth' quest rolling! First up is Forest Grove Marsh. This place is a mess – radioactive water everywhere, and guess who's swimming in it? Feral Ghouls. Seriously, they're everywhere and can be pretty tough. Your best bet is to get to the rooftops ASAP and stay there. Try to find spots with fewer ways for them to climb up, because they will swarm you.

Look for some yellow construction equipment on the north side of town. Use the makeshift ramps nearby to get onto the roof of the building to the south. From there, drop down to a lower roof, then cross a fallen tree to the building to the west. Head south through the ruined second floor of that building and use another debris ramp to get east to a roof. Immediately turn west and go up a ramp to a higher, flat roof. Up here, you can find some Sleeping Bags, a Steamer Trunk, and on a wooden crate near a lantern, you'll find Sheila’s Holotape. Back on the ground floor of that same building, there's some ammo and an [Advanced] floor Safe hidden behind a counter. Keep an eye out for other roofs you can climb, more Ghouls to fight, and a half-submerged red truck on the south-eastern edge of town. You can open that truck to find a First Aid Box and a Large Tool Box. Oh, and don't forget to grab any Mutated Fern Flowers you see growing around town; they'll come in handy later.

Next, we're heading to the Mass Pike Interchange. Leave Forest Grove Marsh to the west and follow the road north/south. The real action is on the large, elevated highway further west. Get underneath it and follow it south until it crosses another highway running east/west. Some Gunners have set up camp right where these roads intersect, both on the ground and up on the highway itself. Take out any you can reach from below. Then, head west and find a collapsed highway segment. It's a bit of a jump, but you can climb up to the elevated highway. To get to the *highest* highway, you'll need to explore the camp under the highways and find a metal shack. Climb the stairs to the top of this shack; there's a button there that calls an elevator. Ride that up to the highest highway. Be warned: this area is guarded by an Assaultron, a Gunner Commander, and a Machinegun Turret MK III. Once they're dealt with, head southeast to find a shack. Outside, there's a Power Armor Station, and inside, on a toilet, you'll find a copy of Grognak the Barbarian. There's also a Trunk in there. In another shack to the north, you can find two Bottlecap Mines, a Caps Stash, an Ammo Box, and two Wooden Crates.

Now, head back to the ground and follow the highway east to the river. You'll need to cross the river here, which will give you some nasty RADS, but it's a quick swim to the other side. As soon as you're across, look up at the broken overpass. There are Raiders up there who will spot you if you're not careful. If you have a Sniper Rifle, try to pick them off from a distance. You might be able to lure one of their dogs down to you, which is an easy kill. You probably won't get all the Raiders from below, so keep heading east and you'll soon be able to climb up the broken overpass yourself to take out the rest.

Once the Raiders are cleared, continue east. For now, ignore the road that heads down into a tunnel and stick to the high ground south of the road. This path will lead you to a Raider camp with some dead Ghouls you can loot, and maybe the Raiders who killed them. Loot everything, then head into a shack to the north and grab two Nuka Cola Quantums from a metal table. After that, head down into the tunnel to find the “Mass Pike Tunnel West” location. We've got a couple of ways to get to Diamond City from here, and we'll cover both. You can go through the tunnels (Mass Pike Tunnel West to Mass Pike Tunnel East) or take the overland route (Hardware Town). Both are worth exploring for the loot!

Once you're down in the tunnel, head east through the northern tunnel. One of the Feral Ghouls lying on the ground will get up and attack – this is just a taste of what's waiting for you deeper in. You can make a beeline for Diamond City now, which is the easier route, or explore this tunnel system. Since we're already exploring, let's dive into the tunnels.

Start by entering a bus. Check out the right side of the bus (the front) for some goodies and to see what the Teddy Bears are up to (creepy!). Out the back of the bus, several Ghouls are milling about. Try to sneak attack them if you can and hold your ground by the bus. Once they're dead, slowly move down each tunnel (left and right) and clear out any remaining Ghouls. Remember, they like to lie down, so try using VATS as you go to help spot them. You might not be able to tell the living from the dead, but VATS sure can!

Now, the left tunnel is the most dangerous, but let's see what's there. The left tunnel has a side hallway on the left with some notable enemies. Head down the left tunnel to the east until you find watery ground where, as we mentioned, Feral Ghouls might be lurking. Take out anything you find, then head into a side chamber to the north.