A desert and a cave

We had decided to fly southward as that was where the aurora seemed to roughly be concentrating.
Mister Gimdalf noticed something amiss with the strange book he had previously used to turn off the geyser. It seemed to be displaying a far smaller version of the everchanging aurora.
With some puzzling and measuring the pattern to a world map he discovered that there seemed to be a set point around which the aurora was swirling. This point was in the desert south of my home mountains.
 
Akta took us straight to our destination in just a few days. Although the epicentre seemed to be somewhere in a large collection of cacti, we couldn't see anything noteworthy from the sky in this plot of land itself. We did see a large crack in the ground east of the forest with signs of life at the bottom. With no real knowledge of where else to go we decided to land on the canyon's floor and startled a group of tortles and a dragonborn.
After calming them down and ensuring them Akta was harmless they were kind enough to answer our questions. With some difficulty due to the language barrier, the Gentlemen and I managed to explain to them that we were looking for the source of the strange happenings and that this should be an extremely old temple. Though they hadn't seen such a building they did inform us that it was likely underground and we could try the extensive cave network accessible from the canyon to find it. After all, if someone was messing around there, there should be a way to get to it.
They'd also been able to see the centre of the aurora we asked them about and instructed us to go roughly two miles westward. they were even kind enough to lend me one of their long-lasting mushroom torches.
 
Entering the caves I took Dar and Din along as there might be a need to climb or decent steep walls. I figured that these two goats would have no trouble getting the three of us to our destination if needed.
With Mister Gimdalf's honed skill of travelling underground we had little trouble finding our way in the dark tunnels. We eventually came to a cavern with several remnants of dead creatures, including a humanoïd skeleton with a journal. The journal told us that they had followed a high priest into the caves to perform a ritual at an old construction but they had no way of powering it. Eventually, the high priest wanted to call in the aid of fiends. The writer had doubts about whether or not such a decision was wise but dared not to say anything.
 
Clearly, this meant we were close to whatever it was we were looking for and there were probably fiends involved. Mister Gimdalfs book had started glowing as well. Indicating something very old and magical was nearby. Not much further ahead we encountered a group of myconids, living mushrooms with telepathic abilities. Mister Macca Ni went ahead of us to see if they were friendly.
The myconids seemed reasonable and kind, though it quickly became clear they had something to do with the cause of the strange magic events and disappearances of gods. We eventually managed to uncover they were imprisoning the gods in an attempt to snuff out the sun and plunge the world into darkness so they could roam above ground. They also let it slip that the high priest from the journal and their followers had died and that, using the information left behind, several myconids had managed to make a warlock pact with the demons.
Since they seemed to intend no real harm I attempted to dissuade them by explaining that a lot of the things living above ground did not fair well without sunlight and it would disrupt the circle of life, harming them in the end as well. However, they only latched on to the information that destroying the sun would make it easier to kill everyone and take over. After that, they seemed to no longer be willing to listen or change their mind at all.
Seeing no other, more reasonable, way to get them to stop their actions, we decided to attack. The initial group was quickly dealt with but another was hiding in the cavern. This one seemed to be one of the few who made a warlock pact with the fiends and quickly ran when we seemed to outmatch it. However, more myconids are coming.
 
I doubt they, the myconids, are truly evil and have been beguiled by lies and empty promises from others. By now they are willingly blind to all the negative consequences of their actions in favour of an illusory dream.