From publisher blurb:
Space exploration is a treasure trove of mysteries for the curious; for those who love to dig deeply into a question to find the answer, or perhaps to reveal even more questions. There is no shortage of strange and wondrous things in the cosmos, and a spacefaring crew will regularly be faced with mysteries of all kinds, at varying difficulty and complexity.
This packet presents ten detailed mission briefs oriented around a variety of mysteries, each of which you can modify for use in your Star Trek Adventures campaigns set during the original series era (approximately 2260-2299) or any other era of play with minor modifications. Each mission brief is designed to stand alone, though they could easily be strung together into a story arc or added to an existing campaign.