The 12th house corresponds to a water sign and is therefore a house of mofcsha (self-realization or final liberation).
Expenditure, waste, misfortune, salvation, final liberation, the state after death, bed comforts (sex life), bedding, confinement, misfortune, hospitals, prisons, secret enemies, "unknown places" (far-off lands), life in foreign countries, hearing (left ear), vision (left eye), feet.
The 12th house is the worst of the dusthanas—the evil or harmful houses. Planets occupying this house are destroyed, as are the houses they rule. The ruler of the 12th will cause harm wherever it is placed. The reason is that since this is the house of expenditure, anything connected to it becomes an expense or a debt. Houses or planets aspected by the 12th ruler are also spoiled.
The more positive side of this house is that it specifically governs moksha, or final liberation. A beneficial 12th house indicates that one may be well on the way to higher consciousness or enlightenment. Also, the state after death will be heavenly and pleasant.
This house also rules far-off lands and therefore is to be analyzed when considering travel.
The karaka, or indicator, of the 12th house is Saturn.
Retrograde lord on the 12th — the person will have less spending, or they will be delayed. There may be trips to overseas countries, predetermined by fate.
Source: «Ancient Hindu Astrology for the Modern Western Astrologer» by James Braha