The Fifth Man by Randy Ingermanson and John Olson

Randy and John liked the interesting setting the created on Mars so much that they decided to write a sequel. I have to say, The Fifth Man is one of the better sequels I have ever read.
Life in paradise seems to be going awry when strange things start happening on the red planet. The crew isn't getting along, and this lack of cooperation is based on a theory Randy and John have studied, of course. Several strange things start happening, such as objects banging on the walls, dark shapes appearing at the windows, and a strange disease wreaking havoc on the four astronauts. On this planet, nothing is as it seems, not even the real fifth man.
The characters stay true to their personalities for a change, which is a plus for a sequel. The romantic subplot is understood though it could do a little better without it.
Once again, all the disasters and suspense is excused by the setting. The main thing that keeps this sequel afloat is the interesting end.
But this should definitely stop here before it turns into a series.
4 stars

Oxygen by Randy Ingermanson and John Olson

If you think a book about space and Mars would be predictable, think again.
Oxygen is a truly thrilling space thriller and Ingermanson's and Olson's best book. The story is about four astronauts who are sent to Mars a mission that is disastrous from the start. Everything starts out on the wrong foot and it's one thing after another. A mysterious bomb explodes and causes one of them to enter a coma. Then a strange form of bacteria is discovered on board. And so on and so forth.
The exciting part of it is its unpredictability. Having that many problems happen at one time isn't very realistic but in this setting it isn't a big deal.
The characters are well developed and interesting to watch and at times, they make the story slightly comedic. The worst part about the book is a slightly cheesy ending, but all in all, it’s really good and leaves room for a good sequel.
4.5 stars

Double Vision by Randy Ingermanson

Double Vision is an intriguing, suspenseful story about five people trying to bring true privacy to America through computer encryption. Dillon Richard is a computer genius, and the brains behind their project.
But someone is trying to sabotage their project, of course.
Their journey is intense and exciting as they race against time to try to save their secrets. The characters are the best he's ever developed. None of them are perfect.
The problem I would raise with the book is the ending. I wish that Ingermanson had done the opposite of what he did for a conclusion. This includes excluding the dumb scene featuring multiple people entering a room and everyone being surprised over and over again. It also includes eliminating the whole premise of the book; the whole Double Vision thing. The meaning of the title is about Dillon having to choose one of two women. His choice is obvious.
However, this is definitely worth reading however because of its realisticness and exciting plot. With Ingermanson's books, you almost wish they would never end because he is ten times better at plots than conclusions.
3 stars