During Holy Week, we often hear the story of Christ's passion that includes his betrayal, trial, and crucifixion. But I've noticed a common trend in three of the four gospels that would suggest that the plot line started much earlier: the anointing at Bethany. Mark 14:3-9 (the anointing) is immediately followed by the betrayal of Judas (Mark 10-11). Based on that same text from Mark, Matthew 26:6-13 (the anointing) is immediately followed by the betrayal of Judas (Matt 26:14-16). In both of these anointing scenes, some of the people watching complain about the cost of the nard used in the anointing. In John, Judas' betrayal (forecast by Christ in John 13:21-30) is foreshadowed by Judas' complaining about the costly nard used in anointing (John 12:4-6).
The anointing scenes in Bethany all occur just prior to Jesus entering Jerusalem and cleansing the temple.
To me, this argues that the passion drama really began with the anointing of Jesus at Bethany, which for someone called "son of David" would be a clear sign of his kingship. The betrayal by Judas Iscariot followed immediately on the heels of this anointing.
Judas Iscariot -- Ιούδας Ισκάριωθ -- can be translated as "Judas of Kerioth," which appears from a map to be a town in Idumea, the historic land of the Edomites south of Judea. Notably, Herod the Great was born in Idumea, a fact that the Pharisees used to object to his legitimacy. Could Judas have been acting out an ethnic grudge?