Einstein showed that all matter is a form of energy, so since energy can neither be created nor destroyed, we have always existed and will always exist in some energy form. No reason to think energy souls don't exist, and quantum physics already proves that multiple dimensions exist.

There could be reincarnation, for that matter. "For us believing physicists, the distinction between past, present and future is only a stubbornly persistent illusion." -Einstein.

what is the exact location of the soul

I don't think there is a soul in the commonly used way. I do think there's a unified body/mind sense in which it's true. A deeper self, so to speak. Though even that is just our perception rather than a fact in the scientific sense.

I agree with other posters that it would depend on how he defines and uses the term "soul". Personally I'd avoid that term as it's heavily freighted with religious meaning and symbolism -- unless I mean exactly what religion means by "soul", which is, the alleged spiritual and immaterial and immortal part of a being -- often used semi-interchangeably with "spirit".

As a physical naturalist I do not believe there is anything "immaterial" or "supernatural".

He may have been using the term as a metaphor for consciousness, or specifically the combination of id, ego, super-ego and consciousness that makes up the core of an individual's personality, rather than to refer to the concept of an immortal soul - but I haven't read the book, so no idea. If so, he'd have been wise to add an explanation of why he chose to use and what he means when he uses such a weighted term, though.