The door will open and you'll run into Holtz (#63). He'll recover you armor and install a sight in your Nailgun. You can recover health too (medic is just few step ahead). Ready for action, go through the hatch. You'll see the Hovertank (#64) - your new ride.
The tank is armed with powerful cannon and machine gun. Steering and targeting is simple, vehicle reacts immediately. During the fight with enemies, remember about energy and armor limit. Tip: you can recharge these parameters - just stop for a while.
Drive in Nexus building's direction - it's hard to miss. Generally, you'll ride in harsh Stroggos planet's scenery. Sometimes you'll also have to ride through wide tunnels (#65).
During the ride, you'll encounter three types of enemies: flying Hornets (they attack with rockers), falling off the sky machine gun's turrets and groups of infantry. The biggest problem will cause Hornets. They are very responsive and quickly escape from machine gun's bullets. The best way to defeat them depends on precise aiming and firing from the heavy cannon. In this place (#66) you'll encounter one more new enemy: fast moving Convoys. Fire the cannon to eliminate them.