Plotinus claimed that soul is not a body nor is it dependent on body. But why is the soul in the body at all and how could soul which is immaterial be in multiple bodies? These questions led Plotinus to the position that it is not the soul that is in the body, but the body that is in the soul.
Plotinus writes in the Enneads IV 3  (O'Meara's translation, page 27):
For the universe lies in soul which sustains it, and nothing is without having some share in soul...
According to O'Meara (page 27):
In other words, Plotinus asks us to reverse our normal way of thinking. We should not think of soul as being somehow 'in' body. In this sense the question as to how soul is in body is badly put. Such is the relation between soul and body that we should try rather to conceive of body as being 'in' soul, in the sense that it depends entirely for its organization and life on soul. A similar reversal is brought about when Plotinus, in VI. 4-5, speaks, not of soul 'going' to, or 'descending into', body, but of body as going to, or approaching, soul.
That is the context of my question and the notion of body going 'in' soul is the focus.
The reason I am asking it is because, after reading O'Meara, I don't know what I should read next.
O'Meara, D. J. (1995). Plotinus: an introduction to the Enneads. Oxford University Press on Demand.