Karma can manifest as illusions and hallucinations. This happens mostly in dreams and certain states of meditation. But only partial karma is manifested in such occurrences.
Full karma manifests at the moment of death. This is called full retribution.
All good and bad karma dwelling in the mind will visit and reveal itself to consciousness.
One thus suffers the visitations and revelations of bad karma and enjoys that of the good karma. This full retribution continues for an incalculable amount of relative time.
Truth is also revealed at the moment of death. But for those who are caught by the indulging illusions and terrifying hallucinations, they would miss it.
Retribution obscures truth.
If the mind is liberated and consciousness is firm and clear, in the moment of death, the meditator will have the chance then to apprehend the truth of life and of the universe.