Six at the top is the hexagram's account of danger that has been allowed to set. The querent is shown bound and hedged about with thorns for three years without having learned what the situation required of them, and the misfortune the text names follows from the second half of that rather than the first. Read divinatorially, this warns of a difficulty that stopped being an event a long time ago and has become the shape of a life, sustained by a course nobody has reconsidered.
The imagery is the Zhou period's own penal vocabulary, cords and a thorn enclosure being an actual sentence rather than a figure of speech, and it is reported here as the text gives it. Its usefulness to a present day reading survives the change of setting because the real subject of the line is the three years and not the thorns. What the text finds culpable is the absence of learning across a full cycle, in a hexagram that has just spent five lines showing that peril can be entered, endured, waited out, worked around and held at a level.
When the line changes, the upper trigram Kan becomes Xun and the figure becomes Dispersion, King Wen 59, in which what has hardened is broken up and scattered. Read from the top of The Abysmal, that is the remedy this line will not name for itself. The thing that has set has to be dissolved rather than escaped, and nothing at this station comes loose while the course that produced it stays unexamined.