Map Key of the Plague Year 4: How The Party Vaporized the Leader of the Apothecary Brigade by Accident

I put a giant death laser in the center of the city and the Party set half the city on fire and blew up the stronghold containing the evil 7th level Plague Doctor. Here's how it worked. Everyone should put giant death lasers in the middle of their cities.

In the Middle of the City of Clargarser stands Raglom's Tower.
Nupo is a friendly NPC. You can see his house.
Clargarser Keep is was occupied by Meelnos Moosit until he was vaporized.

Raglom's tower or "The Panopticon" rises high above the city. At the top of the tower is a giant dome like the top of an observatory. Slightly below this dome are 4 giant glass lenses that jut out from the tower on big metal arms that resemble thin spider legs. The only entrance to the tower is from underground or by flying into one of the many windows on the upper floor.

The Control Panel Has Three Levers not One.

Here is the upper floor. The shaft was going to have a cool wizard elevator in it but Raglom died before he could complete it so intruders must figure out a way to climb the 130' to the top. If you put this in your campaign maybe the wizard will finish the elevator.

Raglom bought the fossilized dragon at auction. The players spent a week in a mine excavating it and then another week delivering it to the auction. If you use something like this put a bunch of stuff the party sold around tower.

For the levers up is off or closed and down is on or open.
Also the labels are wrong for the levers.
The eastern an western one are reversed.

So,  just above the control room in the tower is the artificial star. I made it so that its possible to keep climbing up the shaft to the room with the star and catch on fire and die due to being too close to the star. No one decided to try that after looking up the shaft and seeing the blinding light at the top. I made the tower like this to convey the power and potential danger of the controls in the control room. That way when the party starts messing with the levers and they hear things moving upstairs, they understand that they are messing with something powerful.

The metal shell around the star lowers in two halves, an eastern half and a western half. Lowering a half will blind people on the corresponding side of the city. Light can be seen pouring over the city from the windows if this happens.

The knobs control the positions of the four lenses. The positions of the knobs correspond to the orientation of the lenses so when a knob is turned to the up position the lens is at the north end of tower. When a knob is turned down then it is south. Knobs can be lined up focusing the light and heat of the star even more. Make sure you do not say that the knobs are all in the same position when the party finds it or they will blow things up right away (unless that is what you want.)

Number of knobs lined up and its effect:

    1: Extreme oppressive punishing heat
    2: Immediate sunburn and blindness if the light is looked at. 1d6 damage per round
    3: Flammable burst into flame. metals begin to melt. people save or die.
    4: Vaporization. Enough energy to convert matter into plasma or whatever fantasy reason you have for stuff to just explode. No saving throw. Get out of the way.

If you keep the first lever in the up position you can adjust the other knobs to where you want them then lower the the first lever and everything will move seamlessly into position. This is not what the party did.  They pulled some levers. Blinded the city. Then they put 3 knobs in the same position and set the eastern half of the city on fire. Then they adjusted the knobs together shooting a death ray down towards the south where it was then aligned with the final lens and aimed at the keep, which exploded. Fortunately the keep was where the plague was being manufactured that was afflicting the city. But They also burned down half the city. Then they asked how much xp they got. They got zero.