Plot hole: Why on earth would a sleazeball like Adam Klaus be worried about news of a one-night stand being revealed? He'd welcome the publicity, if anything. Anyone threatening to go to the papers with news of a bit of rumpy-pumpy with him would be wasting their time.
Plot hole: How did the guy who stalked Emma Lazarus managed to get the box containing her head on the aeroplane without it being checked by airport security? As airline passengers are required to have their personal belongings on them scanned, this should have been detected by the airport security scanner and security staff would have detained the passenger or even arrested him before he had the chance to board the plane.
Chosen answer: It was a bottle of turpentine.
Methylated spirit, always coloured purple.