Star Trek Picard: 7 Ups & 3 Downs From Episode 1 'Remembrance'
2. Maddox
Star Trek: The Next Generation is a treasure trove of dangling threads. Smartly choosing not to wrap anything up as it went off the air, it provided sufficient narrative tangents for the creation of both Deep Space Nine and Voyager, with more still left over for three feature films. Even heading into Picard, nearly two decades after it went off the air, there were still storylines from the show that were just begging to be picked up.
Enter (or at least enter a mention of...) Commander Bruce Maddox. Featuring in only a solitary episode of TNG he was one of the Federation's most prominent researchers in robotics and, in 1989's Measure of a Man, takes Picard into a courtroom to argue that Data has no human rights. The show gifts us some of its best-ever writing, and his case is thrown out.
Remembrance tells us though, that he's been busy. Recruiting Doctor Agnes Jurati, he develops his theory of fractal neuronic cloning; which Picard suspects has been used to create Dahj and Soji, two twin, flesh and blood androids from a single positronic neuron of Data's brain. He disappeared after the Synthetic attack on Mars, hasn't been seen since, and looks like playing a major role in the show. A masterstroke.