The wound and the horse make this the most workable line in the hexagram, and its counsel is speed rather than courage. A querent drawing it has taken, or is about to take, a real injury from a situation that has turned against clear sight. The line says the injury is to capacity rather than to survival, and that it should be answered immediately with whatever carries weight and moves quickly. Good fortune here is contingent on the answer being fast.
What the line refuses is deliberation. There is no counsel to determine who did the wounding, no instruction to be firm and correct while enduring it, and no suggestion that a darkening can be reasoned with. The strength of a horse is borrowed strength rather than the subject's own, and a reading landing here usually concerns help that already exists and has not yet been called on.
When the line changes, the lower trigram Li becomes Qian and the figure becomes Peace, King Wen 11, earth above and heaven below, the figure in which the heavy sits over the rising and the two therefore meet. That is a startling destination for a wounded line, and it is the strongest argument the classic makes anywhere for acting at once. A darkening answered quickly at its second stage does not merely fail to worsen. It turns into the figure of things communicating freely, because nothing in it has hardened yet.