The doorway leads you to a circle on the ground that's purple. Next to the circle is a cubicle and a message on the wall. The message says:
"For first timers, put something of yours into the cubicle. This will register you into the database. Use something that contains DNA, like your blood or some hair. For inorganics, putting your hand in there and letting it scan you works as well. Afterwards, step onto the purple circle and think about where you want to go. It has to be within the boundaries of this city, Brockton Bay. When you want to come back here, think about this place. Try not to abuse this function or something could go wrong."
A purple floating message appears next to that after you are done reading it and it says:
"Since you are Heroes, your best option is to think about the local Protectorate building."
I turn around to my team.
"Alright, new city, but business as usual for now. We still need to figure out what's going on here, but it seems that there's heroes like us here."
I pull out one of my hairs and place it in the cubicle, flinching a bit. "Wind, put one of your hairs in here too. Earth, apparently it'll scan your hand, even though, well..."
"Hearing you rock solid, Fire."
Wind and I cringe a bit, before she and Earth move to the cubicle to dispense samples and get scanned.
"Apparently they have teleportation tech; makes sense how they got us here in the first place. Make sure to stand on this circle, and keep on thinking 'local Protectorate building'. We'll get more info on our next move there."
"Wouldn't it be safer to think about our place, use the tech as a ride home?" Wind pitches in.
Recalling the ominous 'you did not exist in this world', I pause for a second, before responding "The message here..." (I gesture to the wall) "... only says it goes in and out of the city. If we think of our place, we might just end up in the most similar location in the city, which might not take well to us barging in."
"Roger, Captain."
"Hey, hey, I have the most seniority here. Why do'ya keep calling him 'captain'?" Earth says, as he sticks his hand into the machine.
"You wanna order us around? My money's on you leading us to the nearest bar." Wind teased.
"Eh, good point."
With that, the team and I step on to the purple circle, and think "local Protectorate building".