Raymond Fowler has been a UFO researcher for apparently much of his adult life, and this book summarises the most "convincing" accounts that have been reported to him. Unfortunately, it is a very frustrating book, although this is probably forced on it by the very limited information. A huge number of reports have seen "unexplained lights in the sky". With no further information they remain unexplained. Some are described in sufficient detail that they would appear to be vehicles (although why they light up like that is a mystery). Here, the lack of detail is annoying. They allegedly then flew away in one of the most intense regions for air travel in the world, so why were not the radar signals reported? In some cases radar signals have been obtained, and it might have been preferable to focus on the few observations with multiple facts and dispense with the rest. It is not the number of sightings that is important; it is the amount of information on any given one of them. One, at least, was allegedly metallic. It was low so what did one individual do? Pulled out a gun and shot at it, and heard a ping. There was one site where a UFO allegedly landed and left impressions from its "feet", and burnt scorch marks. If true, these report vehicles of some sort.
Another piece of frustration was that it seemed to be assumed there was one phenomenon. This may be wrong, thus on one account a "light" followed an aircraft. This appears to be similar to a similar event that I am familiar with. As usual, the information was inadequate, but my guess would be some form of triboluminescence (light generated by pressure on certain special materials in the atmosphere, perhaps from static electricity on water/dust being discharged by the pressure). There were also frequent signs of lights over high-voltage power lines. That might seem to be a specific separate phenomenon.
The second half of the book then changes to alien abductions, in some cases rather frequent ones. My question is, if you were being so abducted and having your brain wiped, wouldn't you try to get recorded evidence? Not these people. So what we are left with is a lot of people saying they saw this or that, but there is very little confirming evidence. There are a number of accounts that people had "forgotten" but were recovered under hypnosis. My concern is, why do we know they were not merely reporting a dream. Some people had circular marks on their leg, which allegedly are the remains of sample collection. My question is, if aliens could cross interstellar space and took body samples using a procedure that left no other sign or effect, and could wipe brains, why did they not simply repair the skin? People can get circular marks on skin.
This is then followed by a number of other odd experiences, such as "out of body" experiences and near-death experiences. I am happy to accept there may be something here, but what has it to do with UFOs, assuming UFOs are real and not some psychic manifestation.
So, where does this leave us? In my case, maybe, maybe not. Insufficient information to be really convincing, but if the people are telling the truth, something weird happens. My overall impression: Too much inconclusive information. The author presents a case that there are a number of things we don't understand, including sometimes whether the person reporting it is reporting real events, dreams, or what. To link "near-death experiences" with UFOs tends to confuse both. You will have to make up your own mind. There is a strong case made that people report weird stuff, but less so a case relating to what it means. It is interesting to read, but I have downgraded it a little because it lacks critical analysis.