When Diggle assesses Oliver's injury after Felicity brings him to the hideout, he states it is a 'Zone 2 wound'. In emergency medicine, this identifies a penetrating neck wound between the collar bone and the angle of the jaw bone.
First appearance of Shado.
This episode is named after Homer's "The Odyssey". In a flashback scene, to make sure the plane doesn't turn around, they have to remember and finish a sentence from "The Odyssey," coincidentally the only book Oliver studied in college.
At around 12 minutes when Yao Fei is in Fyers' office there is a copy of Homer's The Odyssey on the desk. It is under the gun Yao Fei glances at when Fyers turns his back.