Someone did a nice examination of the latest trailer, i think they might have gotten it pinned down what plot is.
this is MY theory, so it's not based but we've seen so far with full trailer.
This series's so far looks like it's basis is based on current events.
Romulans appear to be trying to salvage their Empire or part of them are. They're still xenophobic and they're using fear of the Borg, by gathering former Borg caging them up on a wrecked Borg Cube. Their experimenting on them, either trying figure out their secrets for themselves. The girl in question i suspect is related to the Borg Queen. Picard finally has cause, trying rally support from reluctant Star Fleet to aid saving these people from the Romulans. However, he has to go it alone, teaming up with individuals who are trying to save these people being subjugated or worse.
I'd like remind everyone in First Contact, Picard was very much in camp of not believing individuals who WERE turned into Borg could be saved. That reality was changed with later events of Star Trek: Voyager.
I'm surprised Brent Springer came back. I thought he was done with being Data. He's getting bit old to be playing unaging machine-man, but i like him as actor.