Chapter 8: A Train to Catch
Loot all the containers here then use the fast-travel station outside the gate. Return to Sanctuary and talk to Roland. Like before, you can take on optional missions:
Splinter Group - Tannis
Mighty Morphin – Sir Hammerlock
Positive Self Image – Ellie
Out of Body Experience – Loader remains
Once ready, head to Three-Horns Divide and head to the waypoint leading to the Tundra Express. Once there, go up and kill some varkids with fire to wake up Mordecai. You can also do Sir Hammerlock's "Mighty Morphin" optional mission here.
Meet up with Tina in the marked location. After talking to her and getting your mission updated, head out to search for the badonkadonks.
Head to the Buzzard Academy as marked in the map then clear the area before looking for the explosives. After recovering them, deliver them to Tina then leave her garage as she does the work. Finally, take out the damsels. Before leaving, you can also talk to Tina again to start a series of optional missions.
Head to Meltwater Crossing and follow the markers. Climb the stairs on the platform then set up the explosives there. Arm the rockets then wait until the train gets wrecked. Climb the wreckage and use the portal to End of the Line.
Once there, follow the valley and fight your way through several loaders. Destroy them all and continue until you reach the Terminus Plataeu. Prepare your anti-armor/corrosive weapons and head to the open area for a boss fight.
First, you have to find cover and take out the surveyors. Once theyr'e down, concentrate on using your corrosive weapons to eat up Wilhem's HP. It will continue calling in reinforcements and repair surveyors. These surveyors should be your priority since they restore Wilhem's shields and will harass you if left alone. Besides, they're vulnerable while charging Wilhem's shields.
After defeating Wilhem, grab the loot and its power key then leave for Sanctuary. Deliver the power core to Lt. Davis to complete the mission.