J.Aisenberg to L.H: Vassiliy couldn't have foregone the trip, because he's a character and all characters are as N. himself said, "galley slaves".

Jansy Mello: This point is not very clear in the beginning but later on we shall discover that he cannot leave the group and abandon the planned excursion. The merest hint of subversion transforms him into a “sacrificial lamb” (interesting observation about the intended perforation of his hands and feet using a corkscrew.)

L.H to J.A: I agree that 'ghost' was an illl-chosen word, since it refers to life after death; ghosts are the spirits of dead persons.

Jansy Mello: For Nabokov, ghosts also indicate the fuzzy apprehension of what lies outside our mind: “You can get nearer and nearer, so to speak, to reality; but you never get near enough because reality is an infinite succession of steps, levels of perception, false bottoms, and hence unquenchable, unattainable. You can know more and more about one thing but you can never know everything about one thing: it’s hopeless. So that we live surrounded by more or less ghostly objects…”

This observation is not applicable to Vasiliy, though. A fictional character like him can only be known in the exact measure of VN’s intention. It seems to me that V.Nabokov created him flat, even shadowy like a truly ghostly representative, to demonstrate that it was Vasiliy’s vision, and dreams and fantastic hopes, that which in the end mattered.