In Mark's presentation, Jesus seems to stay in Bethany on Wednesday. Probably he has stirred up a hornet's nest in Jerusalem. Perhaps it is very clear that if he shows himself in the city again, there will be trouble.
The only event Mark tells us about on this day is Jesus' dinner at the home of "Simon the leper." A woman anoints him with expensive perfume. Some of Jesus' followers complain. It could have been sold; the profit could have been given to the poor. Jesus tells them to back off. She is anointing him for burial.
As an aside, Luke intriguingly puts a very similar story in Luke 7 with a Pharisee of the same name. John places a very similar event 6 days before Passover with Mary (sister of Martha) as the woman and Judas as the complainer. It is of course possible that these are amazingly similar events within a week's time, but it really seems more likely that they are different versions of the same event.
Jesus' comment that this woman is anointing him for burial and the idea that people everywhere would talk about this woman later on--these elements sound exactly like the kinds of things that would stick in your mind from the day before Jesus was arrested. It also points to Jesus knowing what was coming. I know most of you never doubted that, but I'm engaging the person for whom these things have to be argued.