The square of Neptune and the South Node points to an old scenario of fog, sacrifice, self-deception, dependency, idealization, secret pain, or escape from reality. The South Node holds the habit, and Neptune makes it soft, unnoticed, and therefore especially sticky. The person may not see for a long time where they are repeating a past scenario.
In the past or in family memory there may have been themes of alcohol, medicine, the sea, religious prohibitions, secret love, sacrifice, a creative gift that never received form, deception, betrayal, or life inside an illusion. In this life, the aspect may appear as the feeling that reality is too rough, while a dream is much safer.

