This adventure, whilst capable of being run as a stand-alone one, works best if you have already played at least some of the adventures in Kafer Dawn and have established the party as competent troubleshoots on Aurore, which is where it all begins. After an Introduction, which explains this and a bit about the contents of this book, there is a Referee's Synopsis that provides an overview of the adventure in quite some detail.
The basic premise is that the party are asked to join Mission Arcturus, which is being sent to investigate why nothing has been heard from the scientific station at Arcturus for about three years. Given that the Arcturus system is only about a day's travel away, you might ask why nobody's bothered until now, but it seems that they were too involved with dealing with Kafer attacks. It was, however, the folks on the station who first reported contact with the Kafers... although it was a couple of years after they'd reported this that contact was lost.
The adventure is well-structured, beginning with An Invitation which covers the party's recruitment. The next section is Aboard the Bassompierre, this being the vessel in which the mission team will travel to Arcturus. The main force aboard, to which the party will be attached, is a company of American Marines, and the next section introduces them. (Those referees playing this adventure 'cold' rather than as part of an existing campaign might care to use the Fire Team One NPCs as player-characters instead of having the party attached to them as advisors/troubleshooters.) There are also a couple of combat walkers aboard, characters with appropriate skills could pilot them (or there are NPC pilots who again could be used as characters if needed). If you are using the NPCs as your party, some advisors are supplied to fill the advisor role intended for your players. It's a neat way of ensuring all necessary roles are filled and giving you various ways in to the adventure, especially if you do not have an existing party suitable to participate.
After a brief section introducing the Arcturus system, we move on to resources about Station Arcture itself. These include its outward appearance and deck-by-deck detailed descriptions... as the idea of the mission is to go aboard and discover just why nothing has been heard from them for so long. Starting with the initial approach and external investigation, the party and others will make their way aboard and deal with whatever situation they find there. There's plenty of material - including some evocative descriptions to read out - to help you run this exploration, when the party pretty much has free rein to go wherever they like on the station. Whatever they decide to do, wherever they decide to go, you will find what you need to run encounters and adjudicate events. Needless to say, this exploration will not be straightforward, with external events as well as internal hazards.
It's a cracking adventure, the classic exploration of a deserted spacestation where anything might be lurking poised to get you, well-resourced and coherent in vision.