When you enter the hub, there's no sign of Ewan, but he's around here somewhere. (Maybe there's a secret bathroom behind one of those computer banks, who knows?) We just need to smoke him out.
Hint 2
Remember how you got him out of the way before? When he hears that temperature alarm, he'll run to the thermostat from wherever he is.
Hint 3
So go back to the thermostat and -- rats, he's put a lock on it. Ah, but he foolishly left himself a note in his lair as to the code, remember? Did you take a picture like I told you?
Hint 4
If not, the code is --
Hint 5
-- like this: #p-O 2 O
O 4 3
1 O 5 #p+
Hint 6
Set the temp to 80 and go hide like before (back, left, forward, left, curve right). But ... now what? We need to keep him in there.
Hint 7
Remember those firewalls? If not, after you hear Ewan stomp past, go to the entrance to the computer area (back, left) and look for a panel on the left wall that says "Firewall Controls."
Hint 8
The bay with the thermostat is B3. Push that button, and Ewan is locked in for the duration. Let's go see what he has to say for himself.