Martian Time Slip is a very downbeat story, albeit with touches of typically quirky PKD humour, and has his usual themes of isolation, drug-use, and mental ailments. It also concentrates, like a lot of his stories, on distorted perceptions of realities, corrupt corporations, conspiracies and time travel. It's a real slow-burner of a tale, the story unfolds very gradually but it draws the reader into it's world and the plights of the various characters, Dick paints a fantastic vision of mars, in fact I'd go so far as to say this is the best novel written about Mars with the exception of Ray Bradbury's Martian Chronicles. The book is certainly the most haunting and atmospheric of the PKD's novels I've read, and has a troubling, dreamlike feel to it. Dick's examinations of autism and schizophrenia relating to it's effects on time is a fascinating concept, and the various characters are all well realised and believable. Overall, I found this to be a very satisfying and stimulating read, one of the finest sci-fi novels I've read and a real highpoint in Philip K Dick's output. Highly recommended.