It's always a bit disconcerting when your warp drive fails. The Synopsis explains what is going on, and what the party will have to do to resolve the situation, and there are notes explaining where to fit this adventure within the timelines of several Star Trek eras, although it's intended to fall in the TNG era of play.
The action begins during a routine trip to check on a lost probe. Just around shift change on the bridge of the party's starship the warp drive fades away and a whole shed-load of alarms go off. Once they have figured out the immediate cause - a massive subspace field - they can then discover some other unnerving problems. They are off-course, and time is acting oddly as well. There's a remarkably strange sight on the viewscreen as well. Figuring all this out is likely to be quite difficult, but some detailed information on likely rolls to discover what's out there are provided and the party ought to get there with a little nudging and the expenditure of some Momentum. There is a wealth of information for the GM to take on board and disseminate as appropriate - this is an adventure that will benefit from some prep time in getting your head around what's going on before you run it!
By the end of the initial investigatory phase, the party should be curious and filled with wonder at finding something hitherto unheard of. They shouldn't feel threatened. To begin with, what they have encountered hasn't even noticed them, and once it does, it's only curious about them. Yet... that disruptive field is only going to cause problems: the anomaly is on course for a Federation outpost! However, when the anomaly gets curious, it starts trying to find out what it has encountered, resulting in a series of puzzles for the party to figure out (once they realise that they are puzzles, that is!). Interestingly, a range of variant puzzles are provided for the GM to choose depending on whether the party is more Command or Science orientated. All are well-supported with suggestions of how to solve them, as well as providing the answers. It's important to understand Extended Tasks for this adventure.
Eventually, the party will meet with an individual, or manifestation, with which they can communicate. Or at least try to... the concepts and background understood by this representative are truly alien, and should prove entertaining (if a bit of a challenge) for the GM to role-play. There's plenty of guidance to help, though, and suggestions as to what can be said and explained. The immediate need is to persuade them to change course, which once the message is got across, they will agree to do so. The adventure concludes with the likely aftermath of this encounter and a few suggestions for further adventures.
This is a very cerebral adventure, which some groups might find dull - others will be entranced and thoroughly enjoy meeting something so unusual and possibly unique. It will need thoughtful GMing to make it work well, but should prove memorable when done well with the right group, capturing the real essence of exploration.