Background
After not using any entheogens for about 8 years, my interest has been recently rekindled. I read a lot about this fascinating topic and for the first time heard about smoking DMT (which was known to me before only as the active ingredient of ayahuasca).
I obtained 500mg of yellowish DMT extracted from MHRB and built a "Machine" to experience this myself.

The First Step (15-20mg)
I weighed around 20mg on my scales (they show mgs but are not very precise for such small amounts) and smoked it in one hit. Before I exhaled, I already had a strong feeling of alertness, foreboding and deja-vu. At the same time the sound of my computer fan (the room was silent) became louder and turned into a vibrating hum. My sight was split in two, as if I saw the room with each eye separately. At the same time caleidoscope-like visuals exploded everywhere - in sync with the vibrating hum. Every contour and every source of light had a prismatic halo around it and everything seemed covered in intricate colorful patterns consisting of strange symbols. Somehow startled by the intensity and to confirm that I am still in reality I jumped up from my chair.
I quickly regained a clear mind and could observe the visuals calmly and almost emotionless. This surprised me as visuals on mushrooms elicit a very strong emotional response in me. Of course it was very interesting to see pictures become three-dimensional, wallpapers breathe and so on; but it seemed to be just a side effect of something much bigger that had not happened yet.


Then it happened (40-45mg)
Some days later I decided to try a bigger dose. I prepared almost the whole day for this, eating lightly, sleeping well before etc. I finally filled the "machine" with around 45mg of DMT at 4:20pm. When the church bells rang for 5pm I was still mustering courage to vaporize this dose. I suddenly decided that it was the right time and inhaled as much as I could at once.
I wanted to lean back on the couch and close my eyes but I honestly can't say if I did. Without warning and without any buildup reality was completely gone.
The whole experience was very direct, unmitigated and just happening. Not necessarily happening to ME but happening in a strangely recursive timeloop that engulfed my complete perception.
I can only describe some elements and there is no real chronology to what I experienced:

The Mantra
I heard a chanted five-syllable mantra in a foreign language that I can't remember now. Mantra sounds very sprititual however it was not, it was more like a riddle, a joke. A mixture of a light-hearted children's rhyme and slightly menacing ridicule. It was continuously repeated and I felt it was chanted by a group of beings being somehow next to me but not in my field of vision.

Perception
I saw many places but everything changed so quickly and most of them had a spatial arrangement that was so foreign I just can't remember or reconstruct it with my sober mind. One place was room-like with a huge two-dimensional blue circle that was flashing huge symbols in all colors. The floor before this was flowing with millions of symbols in all colors. I think I remember this because it was when I could distance myself from the experience for the first time, thinking that it looked very technical, not organic or natural in any way.

Escaping Recursion
There was a menacing and scary element to it. I can't put my finger on it because I didnt have fingers at this time. It had to do with the feeling of recursion, of some kind of loop I didnt understand and couldnt escape.
The beings singing the mantra somehow assumed it was common knowledge how to handle this and jokingly tried to explain it to me in a language I couldnt understand. I remember feeling stupid that I couldnt understand this.

The Hennesy Talisman
The little Hennessy bottle (the machine) was my anchor to reality. I suddenly realized I still held an iridescent form-changing little bottle in my hand. I tried to look at it because I somehow knew I entered the recursion through it so I could also use it to go back to reality. Then it was gone again. The third time or so this happened I was suddenly back in a strongly distorted reality.

Back in "Reality"... kindof
All the cupboards, tables and chairs in my room were tilted, moving and covered with symbols. They looked like they were drawn in a haphazard way with a thick brush. The window (the only source of light in the room) was not showing the outside but a sparkling caleidoscopic spiral zooming in quickly.
My self-awareness returned and I told myself "wow" 10 times in a strangely deep voice.
I just sat there about 10 more minutes looking at a morphing and wobbling room until the visuals subsided slowly.
I looked at the watch and it was 17:30.
I think I was completely gone for almost 20 minutes.


Conclusion
Before I go back I need to read some computer science books and find out how to make sure a recursion terminates

I would have never ever thought something like this possible.
It's so unbelievable. I felt the strong need to write this down not to forget everything.
to force myself to write somehow coherently I decided to do so in your lovely forum.

I hope it's not too long, so if you need a short summary for this wall of text:

Wow!

Great report!

Truly something special. <3

Welcome to the first floor of the rabbit hole, from here on out it gets real weird, your gonna love it

Thanks for the nice feedback.

I am a bit shocked how quickly my memory of the experience is fading. It's not even 5 hours ago and now I can't even remember the rhythm of the chant/mantra which was still echoing in my mind when I wrote the report.


The first floor of the rabbit hole humbled me in a way. I don't know how I could prepare for something more intense. The concept of "accepting and not resisting the experience" might work when there is an ego that can still decide to accept or to resist. I can't imagine how I could even begin to intervene or change something that is so all-encompassing and happening with such a force. My response to the experience seemed to be visceral and not conscious/analytical in any way. This scares me a bit.

It's not only about intensity

I'm not sure you can prepare for it, its beyond preparation.

You can get to a point where 'letting go' or 'accepting it' are no longer relevant terms, it smashes you with a psychedelic 2x4 and all you can do is take the beating, but its a good kind of beating

You can't intervene or change it, but it can easily intervene and change you. I feel your fear is well placed, I offer mine up as a sacrifice, hold on tight and take the ride.

Great report. Welcome aboard. I could relate to a lot of that.

Even in my most ecstatic experiences, fear has always been present, and that slightly mocking element you've described is nearly always there.

There's weirdness beyond all possible imaginings once you open that door, but the next time you do, you'll be greeted immediately with the recall that's currently alluding you. We're just not meant to bring a lot back. The planes don't intersect. For me that's both the most beautiful and frustrating element of the whole deal. It's like trying to catch falling rain with your hands. It just isn't going to happen.

Haahahaha, this is exactly what I said after my third try!

Recursion is important, yes, fractals and all. If you come up with a mathematical explanation, I'd be really interested.

Just my two cents, but it seems that most of the time (for me), when I'm experiencing loops like the one you described, sometimes the source of which is some looping sound in the real world. Whether it be the hum of a refrigerator, air conditioner, computer, etc...continuous sounds have the ability to create these recursive loops. You don't even necessarily have to be aware of them in order for them to intervene. If you do get stuck in a loop, it can be kind of unfortunate (especially depending on what the loop is and what speed it's going at and whatnot), but the best thing to do is to ride it out. If you can calmly sit out the storm, magical things will happen. The alternative is to open your eyes (if you have eyes to open) and this may help to break the loop.

That's an interesting point. I actually switched off my computer during the breakthrough because of my first experience where it turned into this vibrating hum. The only sounds around me were birds singing.

I am still digesting the trip and just now thought about this very question:
was there anything from the outside influencing this?

If yes it was in a way I cannot understand yet. To clarify: during a mushroom trip the things I see (even the CEVs) are in often obvious way influenced by the outside world and parts of my personality (although I might understand this only in retrospect).
With DMT I had the impression all the things I saw and felt were fed from something alien to my conscious self.
I'd like to have seen myself during the trip. Were my eyes open? When? Was there a looping sound? I simply can't tell.
I think I'd need a lot of more experience to be able to correlate outside factors with what I see in this... hyperspace.

Juremo! Thanks for the post... Was really well explained and interesting! Even though I remember some very well indeed, somehow I feel a bit shy to describe my trips, not for any sinister reason, it just feels funny typing about them. You've given me some confidence in that respect! Thanks again.....

....Also, the heart beating is in a way a looping sound I think!

Glad you liked it and I'll be looking forward to your reports from the other side

I am normally also shy to describe my trips and this is the first time I have ever done so. All my other entheogen experiences have been very personal and emotional. I never felt like putting them into words. Let alone sharing them with strangers over the internet.

This time it was easy writing it down. I think it's because describing the alien things I saw with DMT is somehow easier than describing what I learnt from mushrooms. Especially as the latter would sound like hippiesque naive cliches if I tried to talk about it.