When the sub is at the dock there is land surrounding it, but when it takes off from the dock the land is gone and there's open water.
In the scene where Jack swims through the underwater entrance into the Tunnels the very even and smooth bottom of the pool the set was built in can be seen.
When Widmore turns Jack around, a stunt double can be seen.
When Widmore gets off his horse, a hand of a horse trainer is clearly visible for a short time, and the sight and sound of a rope being thrown to control the horse is slightly apparent.
The picture Eloise took of Daniel and Theresa was the same one Desmond found in his office in the episode "Jughead", earlier in the season.
Engines 2 and 3
Before diving, Captain Bird called for a check on engines 2 and 3, which combine to form 23, one of the Numbers.
Once again, the Compass that Richard gave Locke is a confusing paradox. Locke gave it to Richard in 1954, and more than 50 years later Richard gave it to Locke, who then traveled back in time, starting the cycle over again.
All right, let's get started."
This is what Eloise said when the group made it to the cave with the bomb. It's also the exact same line of dialogue she delivered when Jack and the others came to see her in the future before she told them how to get back to the Island.
The leak on Jughead was moved from the tip of the bomb to the body of the bomb.
Charles Widmore references Eloise being pregnant, presumably with Daniel. This would mean Daniel is, at most, 19 years old in 1996 when Desmond visited him as a professor at Oxford, though he was clearly much older.
This is also the second time in which a character sees oneself due to time travel, the first being Miles seeing himself as a baby.
This episode does not contain any character flashbacks or flashforwards.
For the second episode in a row, a scene from the season premiere is shown in a different context.
Pierre Chang asks Hurley about the president of the United States back in 1977, which is Jimmy Carter, who assumed office from 1977 until 1981.
When Jack, Kate, and Hurley got back to the island and were told by Sawyer that the only way to stay safe was to join Dharma, Hurley is worried they were going to be asked questions to which they didn't know the answer. For example, "Who is the President of the United States?" This is what Dr. Chang asked him in this episode.
Ben: I know we've had our differences in the past, John, but I'm here to follow you now. So if you need Jacob to help you reunite your people, then I'll do whatev--
John: I'm not interested in being reunited with my people.
Ben: What do you mean? You told Sun...
John: I know what I told her, but that's not why we're going to Jacob.
Ben: Then why are we going to Jacob?
John: So I can kill him.
Dr. Chang: Your friend Faraday said that you were from the future. I need to know if he was telling the truth.
Hurley: Dude, that's ridiculous.
Dr. Chang: What year were you born? What year?
Dr. Chang: You're forty-six?
Hurley: Yeah...yes I am.
Dr. Chang: So you fought in the Korean War?
Hurley: There was no such thing.
Dr. Chang: Who's the president of the United States?
Hurley: Alright, dude, we're from the future. Sorry.
Richard: (to Ben, confidentially) I'm starting to think John Locke is gonna be trouble.
Ben: Why do you think I tried to kill him?
Locke: What's wrong?
Richard: Something different about you.
Locke: I have a purpose now.
Ben: Your timing is impeccable John. How did you know exactly when to be here?
John: The island told me.
A deleted scene from this episode show Locke shooting the boar he carries into The Others's camp.
A Richard-centric episode.
Original International Air Dates:
United Kingdom: May 10, 2009 on Sky One
Australia: May 20, 2009 on Network 7
Norway: May 27, 2009 on TVNorge
Sweden: June 9, 2009 on TV4
Finland: June 11, 2009 on Nelonen
Latin America: June 15, 2009 on AXN
Denmark: July 3, 2009 on Kanal 5
Czech Republic: July 13, 2009 on AXN
Spain: July 16, 2009 on FOX
Belgium: October 12, 2009 on VT4
Although credited, Henry Ian Cusick (Desmond) didn't appear. Jeremy Davies (Daniel) appeared, but had no lines, except the ones from re-used footage.
20,000 Leagues Under The Sea: Sawyer calls one of the Galaga crewmen Nemo. Nemo is the Captain of the submarine Nautilus in this book by Jules Verne.