4 ideas
Olav Audunssøn, betrothed since childhood to Ingunn, returns from outlawry to find she has been seduced and made pregnant by Teit, an Icelandic clerk. He marries Ingunn and raises her son Eirik as his own heir at Hestviken, carrying the concealed killing for the rest of his life; in old age a stroke takes his speech, so he can no longer confess even when he finally might.
Under medieval Norse law, a killing openly declared was manslaughter that could be settled by atonement payment, but a hidden killing was murder, a dishonorable crime with no clean settlement. By hiding the deed to protect Ingunn's honor, Olav shuts himself out of the very legal mechanism that could have released him.
A wrong that is concealed does not stay the size of the original act. Every year of silence adds new lies, new dependents whose lives rest on the secret, and a heavier cost of disclosure. Confession therefore grows steadily harder even as the need for it grows, until the chance to make it can be lost altogether.
Look at a transgression as answerable to two systems at once, here secular law demanding public declaration and the Church demanding confession and penance. If each system requires an act of exposure that the person dreads, being bound by both means being released by neither. Private suffering or good works cannot substitute for the specific act each system demands.