WARNING: The following contains spoilers for Star Trek: Lower Decks Season 1, Episode 6, "Terminal Provocation," now streaming on CBS All Access.
In the latest episode of Star Trek: Lower Decks, "Terminal Provocation," Ensign Boimler reunited with an old buddy of his from Starfleet Academy named Fletcher. While Fletcher appears to be a fun addition to the crew of the U.S.S. Cerritos at first, he quickly proves to be a total catastrophe. He starts off by taking on a task he can't do alone by letting Boimler and Mariner go to the epic Chu Chu dance instead. Things quickly snowball from there, to the point that lives of everyone on the ship are threatened. Thankfully, Boimler and Mariner are able to solve the problem and save everyone. And as a result of their involvement, the animated series indirectly brings in a fan-favorite character: Star Trek: The Next Generation's William Riker.
To help in his task, Fletcher takes one of the shield array's isolinear cores and hooks it up directly to himself, hoping it will make him smarter. However, the connection works in both directions, and as a result, the core becomes semi-sentient. It starts growing, adding more machinery to itself, and it threatens the life of everyone on board. Thankfully, Boimler and Mariner are able to trap it in the airlock, sending the living core flying right into the Drookmani ship that was also threatening the Cerritos.
While the two Ensigns have the chance to denounce Fletcher for what he did, they instead choose to let him get the praise for their heroic act. And, as a result, Fletcher earns a transfer to the U.S.S. Titan. Then, no more than a week later, Fletcher gets fired from serving on the Titan after throwing trash in the ship's warp core.
Star Trek: Lower Decks takes place in the year 2380, roughly a year after the events of Star Trek: The Next Generation. After the series ended, William Riker moved off of the Enterprise-D and assumed command of the U.S.S. Titan in 2379. Therefore, Fletcher served under Captain Riker for a week, and he is likely the one that ended up firing the Ensign off his ship. We may not have seen Riker in "Terminal Provocation," but he definitely played a role in the episode's events.
Star Trek: Lower Decks stars Tawny Newsome as Ensign Beckett Mariner, Eugene Cordero as Ensign Rutherford, Jack Quaid as Ensign Brad Boimler, Noël Wells as Ensign Tendi, Dawnn Lewis as Captain Carol Freeman, Jerry O'Connell as Commander Jack Ransom, Gillian Vigman as Doctor T'Ana and Fred Tatasciore as Lieutenant Shaxs. The show premiered on CBS All Access on Aug. 6.