[1] As the Trotters are enjoying another evening at the Nag's Head, Boycie and his business partner Abdul ask Del Boy in for a secret meeting, with a proposal that he travels to Amsterdam to buy some diamonds and bring them back to England, without informing Customs and Excise.
The Trotter brothers quickly run off from the police after trying to sell watches that play 36 different national anthems, but they encounter local policeman, DCI Roy Slater, and his partner DC Terry Hoskins.
Despite rebuffing Hoskins' suggestion that the Trotters could be the couriers, Slater mentions that Del is more cunning than he lets on and would be capable of pulling off such a heist.
On the Hull docks, Del decides that, rather than travel through the airports, which Slater is patrolling, he and Rodney should sail to the Netherlands in a hired boat instead.
"Experienced seaman" Albert arrives to captain the boat, although it later emerges that he spent most of his time with the Royal Navy in the boiler room and thus has no experience of navigation.
After getting lost in the North Sea again, the Trotters eventually find their way back to England by following the MV Norland, a ferry which goes from Zeebrugge to Hull.
A few days later, upon returning home to Peckham and meeting with Boycie and Abdul at the Nag's Head, the group are cornered by Slater, who, as it turns out, had arranged the deal with van Kleefe from the start.
Slater makes a proposal: either they all go to prison, or he leaves with the diamonds and they walk away free; the Trotters and friends reluctantly accept the second option.