The first room is the Temple of the Mystery of Abstinence.
Wait until the large man is finished eating to fight him.
If you attack him prematurely, the man in the suit will also attack.
Go through the middle door to the gruesome Mystery of Motherly Love.
After talking to the mother, kill her children, preferably with a melee weapon.
The middle door here leads to the Temple of the Mystery of Religion.
Answer the priest's questions to avoid a (fairly easy) fight.
In order, the answers are:
"Yes", "In Heaven", "Frolic with the Wombats", "I'll take the Staff", and "Trip to Brazil".
Proceed through the door on the left.
Here you can examine a can near the leftmost body for some rations (extra health).
Some boxes on the right hold shotgun ammo, and a gas can next to the grill will fill up your chainsaw.
Continue forward to enter the Temple of the Mystery of Morality.
Kill the soldier, and enter the door on your right.
Mr. Pottsdam has made it into the Lodge, and guards the Temple of the Mystery of Flesh!
After a short conversation, he will attack.
This can be a difficult battle, so consider using one of your ranged weapons.
The next room in the middle is the Mystery of Lust.
If you'd like to spend some time with one of her girls (and avoid another easy fight),
you'll have to give her the $200 you picked up from the cash register.
After a short cutscene, the Madam informs you that the lady you spent some quality time with wasn't feeling too well... you better get to a doctor.
This has a similar effect to the acid from Level 1, and we'll find the antidote a few rooms from now.
Pick up the mirror on your way out to skip past a fight in the next room.
Through the left door is the Mystery of Beauty.
The woman here will ask you if she's beautiful, and if you say yes she'll ask for more and more compliments.
If at any time you stop complimenting her, she'll attack.
However, if you have the mirror in your inventory, you can let her see for herself just how beautiful she is.
Kill her quickly, then exit through the left.
Here is the Temple of the Mystery of Pain.
As soon as the Inquisitor is finished talking, pick up the syringe just to the left of the table and use it to cure your disease.
Attack the man on the table (or the Inquisitor) with any of your weapons until he dies.
Exit through the middle door.
You've entered into the Temple of the Mystery of Charity.
Regardless of what you pick during your chat with the blind man, he will attack.
His cane has a long reach, so you may want to use a ranged weapon.
The room on the left leads to the Temple of the Mystery of Mercy.
You can either agree to kill the elderly couple, or attack the gladiator.
Killing the gladiator will net you his sword, but it isn't very different from your other melee weapons.
Exit through the right opening.
Once you enter the Temple of the Mystery of Remote Control, the man in the middle will summon some enemies to attack.
Depending on how you've rationed your ammo and health until now, this room can potentially be a nightmare to deal with.
The first enemy will be a gun-toting cowboy, and although his aim isn't the greatest, he can be very deadly.
Take him out with any of your ranged weapons, chainsaw included.
The other enemy will be a robot, summoned shortly after you defeat the cowboy.
It isn't very strong. If you want to save whatever ammo you have left, I'd recommend using your flail.
After the battle, the mysterious man will fade away into static, allowing you access into the second-to-final room behind the television.
Welcome to the Inner Sanctum, big guy!
Use a ranged weapon to quickly take out the fez-wearing man in the middle, and then Principal Herrill.
Go through the middle doorway and enjoy the cutscene!