Disjointed and rambling tale of government and corporate plots. The USEA (US and Germany) Government is run by an actress and an android. Cro-Magnon or some other Early Modern Humans have re-appeared in Northern California (I may have met some, come to think of it). Emigration to Mars now takes place in homemade and technically illegal craft called jalopies. This is a weird and wild story, even for Philip Dick.
The book contains most of the usual suspect PKD ideas; time travel, Nazis, androids, paranoia, people not who they seem to be, government plots, corporate plots, etc.
There are a ton of great ideas and I enjoyed the book however it is a bit more rambling than some of PKD's better books. It is worth reading but I wouldn't place it too high on the list. I would say definitely not an entry level PKD book.