1947. The story opens with a response to letter. " I don't think we'll ever learn the truth of what happened at Gruhuken. However I know enough to be convinced that something terrible took place... No doubt the journal would, as you suggest explain much of what happened, but it has not survived, and I cannot ask Jack himself."" 
 1937. The one year research expedition to the Arctic is told strictly through the words of Jack Miller's journal. Jack joins the expedition of 3 other men looking for a communications expert. It is a decision to escape poverty, and why not, since he's very alone in this world. Jack doesn't yet know how "truly alone" feels, but he just might. 
 There are at least two meanings for the term, Dark Matter, in this book. First, as stated in Jack's journal: 
 "In one of my periodicals, there's a paper by someone who's worked out that what we know of the universe is only a tiny percentage of what actually exists. He says what's left can't be seen or detected, but it's there; he calls it 'dark matter'. Of course, no one believes him; but I find the idea unsettling. Or rather, not the idea itself, that's merely an odd notion about outer space. What I don't like is the feeling I sometime get that other things might exist around us, of which we know nothing." 
 Secondly, it concerns the lack of daylight the men of this voyage are about to experience. During the winter period within the Arctic Circle (see Norway's far northern island, Svalbard, in this case), the four months from late October to mid-February will experience Polar Night. This means the sun never rises. By the way, saying 'winter months' sounds so wrong when speaking about the Arctic. I'd call it winter all the damned time. But as I learned, there is winter and there is Winter. Same is true for the dark, and its effects on the human mind. 
 "In a month, on the 16th of October, we'll see the sun for the last time. According to the books, there'll still be some light for a few weeks after that, because at noon the sun won't be all that far below the horizon. They call it 'midday dawn'. After that, nothing." 
 When Jack, Gus and Algie finally arrive by ship to their destination, they know that the captain believes the place is haunted. Something bad has occurred here. It's only a feeling. All that speaks of past human inhabitance here is an abandoned mine and an old trapper's hut that leans against the rocks above the bay, but Jack sees something else on the first day. "The one who walks." I won't go into the plot any further here, except to say that he will end up alone. There could be no other way, right? 
 "But the thing to remember, Jack, is that it's only an echo. It's like a footprint or a shadow. It can't hurt you. All it can do is frighten. After that, nothing." 
 Well, maybe Jack's not quite alone.