E2M4: The Ice Grotto (Heretic)

E2M4: The Ice Grotto is the fourth level in the Hell's Maw episode of Heretic. It contains an entrance to the secret level E2M9: The Glacier.

Walkthrough
The level is divided into two sections, one with ice and another with a village area. They are seperated from each other with a large castle wall. In a small cave, there is an Ethereal Crossbow. Picking it up will open a hidden door closer to the starting point which holds a Tome of Power and counts as a secret. Scan the maze of rocks until you find the yellow key. After retrieving it, go for the yellow door at the large building.

Inside the building, there are alcoves of gargoyles, and a Phoenix Rod. Take out the gargoyles, pick up the weapon and prepare for a gargoyle attack as a couple of doors open in the hall. Once you have quelled the attack, you will see a teleporter on one side of the door. Go through it and expect to be ambushed by a disciple unless you happen to telefrag it. Turn towards the edge of the level and you will see a window with an Inferno Orb on the window sill. Try to jump for it and then go back into the building. A second teleporter has opened on the other side of the door. Go through it. This is a repeat of the previous teleporter, except that there will also be the green key. The window sill next to it holds another Inferno Orb.

Now that you have the green key, go to the green door which is near the start of the level. Take out any monsters inside the room behind the door and go through the teleporter. The teleporter will take you to the very top of the castle wall. Unless you decided to take out the enemies patrolling the bridge from below earlier in the level, you may be surrounded. Either take out all of the enemies so that they do not bother you again or simply jump down into the village area.

Scan the village area for buildings that you can enter. The most important building to enter right now is the one with a Torch near its entrance and a lava pool inside. Go up the stairs in this building and start going down the hallway looking to the rooms inside. The room of interest is a dark room with some gargoyles and a switch in it. Take the enemies out and press the switch. This will open up the building with the blue key in it.

Get the key, obtain the Wings of Wrath in the small building and head for the blue door. Go up the stairs and take out the sabreclaws. At the end of the staircase, there is a round chamber. Kill the iron lich and the gargoyles there and then proceed to another stairs to the exit room, which contains a disciple.

Secret exit
This level also contains the exit to the episode's secret level. To access it, head up the stairs toward the normal exit, but do not use the teleporter.

You can use the now available teleporter into the building just North of the Blue door, or a Chaos Device or the Wings of Wrath to get back to the beginning of the level. Now go back to the building with the yellow door. The door at the southern end will be open now (you crossed a trigger when you walked up the stairs toward the normal exit). At the end of the passage, there is another exit teleporter. The teleporter will take you to the Glacier.