
click to enlarge
When you're back the previously closed doors will be open. a blue Soldier Ant will appear. With the Varsity Glove, they're not so tough now. 3 zaps and they're toast. Ride the lift and go down. You'll see a robot. Scan it of course. It's Barry the Maintenance Bot. Open the chest behind him, then talk to him.
He'll task you to protect some turrets from those pesky ants. Kill the pests that'll pop-up and enter the portal. Once you're inside you'll face around a dozen ants before you can proceed. Kill them and the force field will go down, enter and you'll see the turrets. Scan one (Ant Defense System) and heal up if necessary. Go near the turrets to trigger the swarm. Besides your usual grunts and soldiers, a new ant monster will appear: the Sniper Ant. Scan one of the flying critters then use your Disassembler to knock them down, then finish them off with a few zaps. After clearing the area of enemies, the monorail and the lift will arrive.
Take the lift and ride the monorail. The monorail is different so scan it for your collection. Use the Call Box and select Transit Station. Return to Barry to open the transit system.
Once it's open, you may opt to return to the Robinson House to build stuff and get upgrades, or you may choose to proceed to the industrial district.