I've read hundreds of books and thousands of short stories and not come across a premise quite like this. A technology has been invented that allows people, or anything for that matter, to be stoned. We might call it suspended animation. The Earth has become overpopulated. What it's being used for in this story is stoning everyone for six days out of seven. You share your apartment with six other people (or couples) who are stoned while you're awake and vice versa.

He does mention a couple other uses of stoning. You go to a restaurant, you order something, it may have been prepared a week or a month ago and put into a stoning chamber. The other that comes to mind is travel, you have yourself shipped to your destination during that six day period when you're not conscious.

The law is strict about you living only on your day of the week. People who don't go into their stoning chamber are daybreakers. So the story here is that unbeknownst to the rest of humanity a group has found a drug or something that will vastly increase their lifespan. An immer might live for hundreds of subjective years.

The immers need people to carry the occasional message between the days. So a select few like Jeff Caird are daybreakers that have been set up with seven different identities. On Tuesday Jeff is married to Ozma, he is an organic, what we would probably call a policeman or police dectective. He's given a case to catch a daybreaker.

As the week progresses we see each of Jeff's different identities, and how he changes his psyche to fit that personality. Normally each day is completely seperate from the day before and the day after, but this particular week Caird/Tingle/Dulski/etc. is caught up in a story that is crossing day boundries.

I thought the book was great. There was a chase scene near the end that seemed to go on and on. Maybe the idea was to get the reader as tired as the chase participants. Definitely worth the $2.50 that I paid for it.