At Heathrow Airport’s busy immigration desk, a newly arrived Jamaican strolls through with a kilo of top-grade cocaine strapped to his body. And keeps on walking . . .By the time the syndicate get to hear about the missing consignment, D is in business — for himself — as the Front Line’s newest don.But D’s treachery will never be forgotten — or forgiven. The message filters down from the Yardie crime lords to their soldiers on the streets:Find D. Find the merchandise. And make him pay for his sins…