Jimmy has been trying to convince people that Davis is a serial killer since "Turbulence". In this episode, Oliver praises him for being the first to recognize this.
This is the last episode to show the coffee shop portion of the Talon.
The Fortress of Solitude was last seen in "Legion" where Brainiac had drained it of all its knowledge, killing Jor-El's connection to it.
In Chloe's nightmare, as Chloe walks down the steps, there are movie posters with the title Lobo's Road Trip. In the comics, Lobo is an intergalactic bounty hunter.
When Chloe arrived at the Fortress, she removes the black crystal that was opening the portal to the Phantom Zone. However, in Season Five's "Solitude", Brainiac tricked Clark into using this crystal, stating "I couldn't have done it without you. You're the only one who could affect the Fortress." This alludes to Clark being the only one who could insert or remove this crystal at the Fortress, something that was also brought up in Season Seven's "Blue" with the crystal that Zor-El uses on the Fortress. Kara tried to remove it but was told by Zor-El that only Clark could remove it. However, the Fortress is still in its damaged state after "Legion", and this might have something to do with it.