The Borg are revealed behind Jack's visions, Starfleet's young officers are assimilated on Frontier Day, Shaw dies, and Geordi reveals the restored Enterprise-D.
Troi learns that Jack's visions come from the Borg, and that Picard's supposed Irumodic syndrome was really hidden Borg biology from his time as Locutus, which passed to Jack. The Changelings used Picard's stolen body to place this code in Starfleet's transporters, altering officers under 25.
Jack seeks out the Borg Queen and is assimilated. On Frontier Day, Fleet Admiral Shelby links Starfleet's ships through a new fleet formation system, letting the Queen take over the fleet and its young crews; Shelby is killed. Shaw dies helping the Enterprise-D veterans escape and hands the Titan to Seven. At the Fleet Museum, Geordi shows the crew the restored Enterprise-D. Terry Matalas directed.