The name Vier is German for the number four.
The name Fünf is German for the number five.
The name Sechs is German for the number six.
The name Sieben is German for the Number seven.
The name Acht is German for the number eight.
The name Neun is German for the number nine.
The names of the Zahlen Schwestern are Vier, Fünf, Sechs, Sieben, Acht and Neun.
The name of the group of assassins featured in this episode is Zahlen Schwestern which is German for Number Sisters.
Cal's line "Are you talking to me?" is a reference to the famous line from the film 'Taxi Driver' starring Robert DeNiro.
Cal's line "Do you feel lucky? Well? Do ya, Punk?" is a reference to the famous line from the film 'Dirty Harry' starring Clint Eastwood.
Scythe Master's real name is revealed for the first time in this episode, it is Dr. Giuseppe.
Lizzie's full name is revealed for the first time in this episode. It is Elisabeth Garland.
The pictures that Scythe Master takes of Ein in this episode are the same as some of the still shots we see in the opening credits for the show.
At the end of the episode we see that Ein has been looking at a travel brochure for Mongholia this is significant as it is revealed at the end of the Game and the OVA on which this series is based that this is where Ein is originally from.
According to his fake passport Zwei's cover identity for the mission is: Wallace Yang, a resident of the state of California. All other details on the passport are unreadable.
The terrorist group initially blamed for the FBI agents death, Noche de Sangre, is Spanish for Night of Blood.
At the start of the episode when Claudia is looking at Zwei's passport you can clearly make out the following details: His full name is Reiji Azuma, his nationality is Japanese, his sex is male and the passport was issued on March 27th. All the other details are obscured by Claudia's hand.
When Ein is talking to Zwei at the start of the episode she absent mindedly traces the outline of a number '2' in the dust this is a reference to the fact that Zwei is German for two.
When Zwei is learning to shoot from Ein he is using Ein's signature revolver and not his own semi-automatic to do so.
When Ein threatens Zwei at the start of the episode she does so with a semi-automatic handgun and not her signature revolver. She then hands the pistol to Zwei - this is because a semi-automatic pistol is the signature weapon of Zwei in the game on which this show is based.