It's vanished like his predecessor in the film! Well, not quite. McGregor gets a call to work as a ghost writer on the memoirs of the ex-Prime Minister of England (Pierce Brosnan) after the original ghost writer somehow manages to get tossed off of a ferry and drowns. Getting paid a handsome quarter mil for a month's work, the Ghost takes the job and realizes pretty quickly all is not quite right with the situation. The plot twists and turns and while the mole is never revealed, the bad guys are as the Ghost finally figures out how to read the clues to the mystery of the first ghost's disappearance. The ending contains enough ambiguity for a fun discussion afterward as to who was zooming whom and I'd watch it again to see if there are some clues left in plain sight that are just hard to catch in a first viewing.
The cast is uniformly solid, with Kim Cattral, Tom Wilkinson and an almost unrecognizable bald James Belushi turning in fine supporting performances. MAP thought Brosnan was too big a persona to disappear into the PM's role, but having never seen Brosnan as Bond, I didn't have that problem with the casting. Olivia Williams is excellent as Ruth, Lang's wife who walks a thin line through the entire film making one wonder if she's Clytemnestra or Cassandra.
The script by Robert Harris (based on his novel) is pretty straightforward and well-written with one exception that is an unfortunate necessity to make the plot move forward. It's a distraction, but not a major one. Should I tell you? Sure, it's not quite a spoiler. When the Ghost moves to the PMs house to avoid the press as a scandal erupts around the politician, he finds himself placed in his predecessor's room, which curiously still has all this belongings in it. Seriously? The house has staff, and they would have cleared the room to make way for its new guest. But ah, the writer needed to have the Ghost dump contents of the drawer into a suitcase himself in order to discover the hidden photos(!), leading down the path to uncovering the truth behind who is really doing what, to whom and why.
As for McGregor, he disappears into the role of the ghost so smoothly- like his new, mole-less forehead.
See it. Polanski needs the money for his legal fees, Wilkinson and Catrall are pleasures, and if it's a big enough hit perhaps McGregor can offer a ransom and get his mole back in time for his next film.