The novel is set in a fairly near future where various corporations have clubbed together to send a manned mission into space. The mission is simply to explore, to go further than mankind has ever been, and it is hoped that the expedition will capture the public imagination and spark enthusiasm for future space travel. The crew consists of six people, all picked from thousands of applicants for their particular skills. Our narrator is Cormac, a journalist whose job it is to document the trip, and the only one with no technical or scientific knowledge.
Things have already gone horribly wrong when the book begins. The crew have all died one by one in different ways, and Cormac is alone, unable to turn back the ship to return to Earth and trying to reconcile himself to the fact that the oxygen will soon run out and he will die. The first part of the novel is simply his thoughts as he ponders his impending doom; his memories of the trip, his longing for his wife and parents who he will never see again, and emotions which swing from denial to determination and ultimately despair. It's very affecting - in fact, probably the best part of the novel - and Cormac's loneliness, the clinical setting of the spaceship, and the black void of space all combine to give the book a cold, dark atmosphere that's guaranteed to give any reader the heebie jeebies.
Then something unexpected happens. I'm not going to tell you what it is, and I'd urge you to avoid Amazon and anywhere else where you might stumble across a spoilerific review, because half the fun of reading this is in being surprised. There are some very nifty plot twists in The Explorer, each one revealed at optimum moments to keep the reader hanging on the edge of their seat. I reached the point of no return at about 11pm, and knew very well that there was no way I'd be getting any sleep until I'd finished it.