You start in an open courtyard of a chapel-like building, adorned with stained glass windows depicting the three character classes. The area is filled with Ettins, although you are not in danger until you move or attack. With the only other paths blocked or locked, you need to enter the main doors.
In the main hall, you will see a closed teleporter. There are also two traps in the room. First, stepping near the teleporter will release monsters, and the second is triggered by approaching the southern alcove, causing them to turn and shoot projectiles. There are a few flechettes near the alcove and teleporter, and health behind the northern and western stained glass. To continue, smash the warrior stained glass window in the western alcove to reveal stairs.
Proceed down the stairs, and pull the switch on the left and proceed through the four opening doors. When you enter the next room, the sides of the walls will lower to release a few ettins. You can smash the back stained glass window for a Quartz Flask, or pull the switch to reveal the Emerald Key.
When you collect the emerald key, the four doors begin a crushing sequence. When the fourth door closes, run against the doors. You should blitz through as soon as it opens, and before the first starts to close. If it does close, you were moving at walking speed. Return to the starting area.
To the south-east of the start, you should find the Emerald key door. Open it, and Ettins will begin their attack. You will now need to get through the gate. First, press the switch to open the side door and go up the steps. Take care of the Ettin guard, and press the switch at the top of the wall. Return down the stairs, and the bell tower is now accessible.
The bell tower is locked by a silver key, accessible from a cave north-west of the tower. When you collect a silver key, the crushing hallway will commence, but is not as dangerous. To pass through, simply forward as the ceiling and floor retract.
Enter the bell tower, and head to the top to ring the bell. This will spawn a few monsters, but unlocks the exit.
This exit is a point of no return, despite being in the Seven Portals hub.