Ryujin
Legend
Clearly, the writers were cribbing from Kelis the Poet, from season 6 of "Voyager."While I wish it wasn't the Borg again, as an abrupt episode 9 reveal I think anything else would have just been more disappointing. To me the sin lies with the fixation of serialized television with big mystery box reveals, not in putting the most suitable thing in the mystery box.
Mutated changelings infiltrating Starfleet were more than enough of a threat to fulfill the villain quota here and were being established over the course of the season, but the style of the time is to think viewers need to have a big reveal (which they do when the show has nothing else to offer, but that's not the case here). It doesn't ruin the season for me by any means, it's just unfortunate that the writers felt compelled to do a big mystery, when such things are almost invariably disappointing and primarily serve to get audiences to tune in next week, when most viewers of this season were going to keep tuning in anyway on account of it being actually a good show. The need to end every episode on a cliffhanger (including episodes 7 and 8 infuriatingly using the same cliffhanger) is a related and similar insecurity about the show retaining its audience, and collectively these manipulations out of insecurity are the weakest point of season 3 Picard in my book overall.
"Mistaken identity - a character who is someone else. Discovery - the moment when that identity is revealed. Reversal - a situation that turns from good to bad in a blink of an eye."