The scene in question involves the evacuation of D’Qar, which is the planet where the resistance is based during The Force Awakens. In that film, General Organa makes a point of saying that the Resistance base is a target and Making Star Wars says that the First Order “follows through on that but they wait until the start of The Last Jedi to get to the destruction because Rey and the Resistance took down Starkiller Base.”
As for the details that the book offers on how that will play out, here’s the description:
After Poe Dameron’s squadrons destroyed Starkiller Base, the First Order sought out the Resistance headquarters on the planet of D’Qar to enact their revenge. A-wings flew guard around the Resistance fleet and the transports fleeing the base. When three First Order warships emerged from hyperspace to attack, a squadron of A-wings, commanded by Tallie Lintra, assisted Poe Dameron and the Resistance’s assault bombers in taking on an enemy dreadnought.
This certainly sounds like it would be a fun action-packed opening sequence to The Last Jedi, but as of right now, we don’t know for sure if this will be a part of the film. I figured the film would pick up right where we left off with Rey and Luke. We’ll just have to wait and see how it all plays out! This whole thing could end up being a scene later in the film.
Star Wars: The Last Jedi will be released on December 15th.
Source: Jedi Bibliothek