The TNG novel is now set for release in October. As the new blurb mentions, it will be focusing on Picard in the aftermath of the exposure of Section 31 in Mack's Section 31: Control, and will also be a follow up on Mack's older TNG book A Time to Heal, in which the crimes alluded too below occurred:
From the New York Times bestselling author of Star Trek: Discovery: Desperate Hours comes an original, thrilling novel set in the universe of Star Trek: The Next Generation!
The past returns to haunt Captain Jean-Luc Picard—a crime he thought long buried has been exposed, and he must return to Earth to answer for his role in a conspiracy that some call treason. Meanwhile, the U.S.S. Enterprise is sent to apprehend pirates who have stolen vital technology from a fragile Federation colony. But acting captain Commander Worf discovers that the pirates’ motives are not what they seem, and that sometimes standing for justice means defying the law….