As they approach the main Tower, some Guard say “Stop or I’ll shoot” ! Through the arrowslit that is a the entrance of the gate.

He seems terrified.

An army is coming from the outside to intercept them.

The porticulus control is not accessible, so they have to find a way to convince the guard in the guard tower to close it.

If they don’t find any good ideas, they can fight the guards and lock themselves in the tower.