I am trying to remember the name of a book I read when I was a teenager about 20 odd years ago. I think it was written in the 70's or 80's.
The premise of the book as I remember it is as follows.
There are two universes.
The first is Earth but set in the future relative to the date the book was written. A means of creating free energy has been discovered; I think it is being removed from an alternate universe, but a scientist has discovered that this has the potential to cause problems for the planet.
The second story line runs parallel and relates to a being in an alternate universe travelling through that species' version of puberty. At the start, this being (I believe it is referred to as male) is young and is romantically attached to a female of the species. They are described as being a type of energy that changes colour. She develops and changes into a different type of being and he resists changing. There is a third male that he is jealous of. At some point, however, I believe he then accepts that he must grow and he changes and then melds with the female and other male to form a combined consciousness.
I never got to the end of the book; at the time I found it a really hard read, but I found myself thinking about it the other day and wanted to try and find it so I can give it another go.