I've been a huge fan of the Alien: Covenant marketing campaign that along with a few trailers has been using short films to promote the feature. This is a much more effective way in building hype than dropping 10 trailers that spoil various scenes or 10 trailers that are just the same scenes with different music. The first short film was Alien Covenant Prologue: Last Supper and was directed by Ridley Scott's son, Luke Scott. This second one called Alien Covenant Prologue: The Crossing doesn't have a director attached to it, but I have my suspicious that this was initially in the movie but now has been cut to create a short movie. Check it out (warning, this will contain some spoilers and stop you from going into Alien: Covenant cold), then read some of my thoughts on it below.
The Last Supper was pure character development and I assume was showing us what the crew did right before we jump into the movie. It did not contain any plot or really even reveal what to expect. On the other hand, The Crossing has some huge storyline developments and answers some questions that have been lingering since the movie was announced. The big thing is we finally get to see Noomi Rapace's Elizabeth Shaw, whose absence from the movie marketing was the biggest question mark. The short thankfully still does not spell out her fate or why Noomi only has an uncredited role in the movie. It gives me hope that she will still be alive at the start of the movie or at least it shows David probably was not directly responsible for her death (if she indeed does die, which I think everyone at this point assumes).
We now know that David and Elizabeth get along at some level. David is touched by her willingness to repair him, or at least as much as an android can be moved emotionally. We also know that they did reach their goal of making it to the planet of the Engineers. Elizabeth also seems optimistic that the meeting with the Engineers could be a positive one, despite all that happen in the last movie. Not sure how she can cling to that hope, since the last Engineer tried to kill her, but points for a positive attitude.
The real big story development and what can only be seen as a spoiler, is that David exacts revenge for his decapitation by unleashing the alien pathogens on the entire planet. We don't see it, but the Engineers are probably wiped out or at least most will get a nasty face sucking. Now, we know why the crew comes upon an uninhabited planet and that David was responsible for the horror that bestows the unlucky crew. Watching it does make me think this had to be scene that was cut out of the movie.
Even if it isn't, I can't shake the feeling that I witnessed what would be the mid movie twist. It has to be revealed to the crew at some point that David did this, unless the short film is building right into the introduction of the movie where we see David unleash his plague. Even though I get a sense we got some answers here, it does leave a lot of lot questions.
Shaw isn't there when the crew arrives, so what does happen to her? Why doesn't David do his nasty deed then fly out of there? What purpose does he have staying on the planet? How long ago was this act to when the crew arrive to the planet? Why don't more movies do these awesome short films that get the viewer asking way more questions than a traditional trailer?
My sense is this setting up not only the xenomorphs but David as the antagonist in the movie. I'm intrigued to see if this was really an act of vengeance or still part of David's initial programming that cause him in Prometheus to infect crew members as well. I look forward to seeing how they incorporate these revelations into the main movie, and I have a lot of confidence we may have the first great Alien movie since 1986.