As soon as you pick up a book in the first person, you have to ask yourself, is this person an unreliable narrator. Imaginary Friends is narrated by social scientist, Roger Zimmern, who seems genuine, and he is one of the four main characters in the book, the others being Thomas McMann, Verena Roberts and Elsie Novar, Verena's aunt.
Roger and Thomas McMann set out to do a sociological study in the small town of Sophis. On the face of it, Roger's role as narrator of the book, is not to participate in the story, but to observe and report - and of course, that's precisely what is he supposed to be doing at Sophis, where members of a spiritualist cult group called the Truth Seekers, led by Verena, are supposedly receiving messages from outer space. These messages are coming, via Verena, from beings called Varnians floating around in the heavens, lead by Ro - names that are strangely reminiscent of Verena's first and surname.
Over a period, Roger and McMann infiltrate the sect, but neither remains sufficiently neutral. Roger in spite of his efforts, falls in love with Verena and has to work hard at rejecting what seem to be advances from her. McMann, in the meantime, does not abide by the social scientists' code of being non-directional, and gradually gains more and more prominence in the group.
There are many really funny moments during the novel, which I don't think is meant to be taken too seriously. A book could have been written about the dangers of some cults, but this is not it.
I found it humorous and unusual; and though I enjoyed the plot, it was the relationships between the main characters that mattered to me, in the end.