The effect of this story and the earlier one in chapter 11 is to show Jesus knowledge and complete governance of events as his hour of death approaches.
Jesus is not a tragic hero caught in the wash of events beyond his control.
There is no hint of desperation, fear anger or futility on his part. As the commentator Edwards notes, Jesus does not cower or retreat as pilots are hatched against him.
He displays, as he has through the gospel, a sovereign freedom and authority to follow a course he has freely chosen in accordance with god’s plan.
Judas and others may act against him, but they do not act upon him.
Mark 14:12 On the first day of Unleavened Bread, when they sacrifice the Passover lamb, his disciples asked him, “Where do you want us to go and prepare the Passover so that you may eat it?”
13 So he sent two of his disciples and told them, “Go into the city, and a man carrying a jar of water will meet you. Follow him. 14 Wherever he enters, tell the owner of the house, ‘The Teacher says, “Where is my guest room where I may eat the Passover with my disciples?”’ 15 He will show you a large room upstairs, furnished and ready. Make the preparations for us there.” 16 So the disciples went out, entered the city, and found it just as he had told them, and they prepared the Passover.