It happens on the 39th, every time.
The human body is a strange thing; as our interface to the outside world, it is deceptively simple.
The human brain is even stranger; new signals from the body are interpreted relative to the last state.
However, the strangest is the memory.
Six weeks ago I was standing against the same rusty railing, feeling the same rusty bolt against my palm and the same uneven plank under my feet.
In spacial terms, I was in exactly the same place, travelling at exactly the same speed... but in the opposite direction.
That time I was wearing nothing but a ragged pair of shorts.
This time I am dressed head to toe in furs, looking at the speck on the horizon in exactly the same way but with a sheet of scratched perspex crudely strapped across my eyes.
Now that I am so close, I already begin to feel the warmth, although I know it hasn't yet arrived.
At this point last time, I was still warm; gently and slowly adding the layers of clothes I knew I would need: trying to pretend to live a normal life for as long as possible.
I resist the temptation to strip off; I force that intelligence past the failure of my bodily senses, brain and memory... think of Jarn.
Jarn No-Toes, Jarn No-Fingers, Jarn The Cripple.
Wait until you can see the whites of the tower; wait. You are in a bubble, you cannot really know but by sight alone.
No-one distracts themselves by taking in the spectacle around them; maybe the first time, but not after.
Spectacle it is though... a hundred silent figures hunched against the wind; stock still; watching, looking.
For anyone fortunate to be watching from the direction of our destination, the sight would be disconcerting.
Why the gaps?
A sign of poor vantage? An invisible obstruction?
A message? A human bar code? 
It is a message, but not in its entirety.
Each gap tells a tale to those that know.
Three to my right is the gap that was Karek, five to my left the gap that was Marl; and so on; and on.
That message will be gone again in six weeks, when I'm in my shorts and fumbling at my cul-de-sac for my second glove, trying to time my encapsulation to perfection.
The poor soul that is then the gap that was Karek will be looking around, watching what the others do, desperate not to make a mistake.
Whomsoever it is might even ask, but they'll get no response; the rapture that is to be had blocks out all of the senses that don't provide it.
Quarfi breaks first; a glove is off.
He alternately shields the naked hand under his armpit and places it in front of him in the breeze, trying to see if his cold-numbed fingers are warming up.
The problem is that the body produces a conflicting response: in the event they are warming a tingling sensation followed by some pain then a strong, heightened sense of feeling: the rapture.
In the event they are rapidly cooling a tingling sensation followed by some pain... then nothing.