Since the kidnapping insurance that Lloyd's of London has supplied to EuroCopper, the mining combine, won't cover the ransom Dr. Elyse Revelle's tribal captors demanded when they snatched her from her clinic in Zaire, Lloyd's needs somebody to head into the heart of darkness and negotiate the amount--somebody who doesn't have any inconvenient friends or relatives who might make a fuss if he disappears. Enter expatriate American Mitch Roberts (Rude Boys, 1992, etc.), whose cute scheme, hatched together with his native contact Adam Mbenga, to swap the ú75,000 ransom for an equivalent sum in uncut diamonds seems to put him at risk from every thug in central Africa. Sedate and dankly atmospheric, even before Roberts comes down with cholera. Be warned, though: despite its greater length and self- seriousness, the plot is no more than an overdrawn anecdote.