In the penultimate Season 4 episode of Star Trek: Lower Decks, the crew of the USS Cerritos was sent to find The Next Generation character Nick Locarno. Along with him, there came a list of names of former Starfleet officers the Federation had lost touch with, including Beverly Crusher and Seven of Nine. While Star Trek: Picard satisfactorily caught up with them, the final name on the list is a big question mark. Lower Decks could tell the story of Thomas Riker, last seen in Star Trek: Deep Space Nine being sent off to Cardassian prison.
Source：https://www.cbr.com/star-trek-lower-decks-thomas-riker-deep-space-nine/
