A story about a fictional South African police base on the border between Angola and the former South West Africa. While patrolling, a mail convoy is ambushed and most of the soldiers are shot. The captain is rescued, but one of his constables is taken prisoner. The constable’s sister is also the captain’s girlfriend. GRENSBASIS 13 (Border Post 13) tells the story of the captain’s suspenseful and action-filled rescue attempt in order to bring his sweetheart’s brother home.
A detective agency gives a complex smuggling case to the seemingly absent-minded PI Boetie Flenters - never thinking he will solve it. Monica Terblanche (alias Hester Smith) is blackmailed to smuggle diamonds by Da Silva (aka Hennie Gous) and his accomplice. In return, she will receive the negative of an incriminating photo of her father. The investigation takes Boetie to the village of Geenfontein. When he bungles things he is fired and takes jobs as a bus conductor, hospital porter, lifeguard, lounge singer and plumber. Then he meets Hester, who explains her predicament, and they decide to work together.