Twenty years ago, crooks John and Ron were able to hide the diamond they stole in young Gert's football at the Old Castle Inn owned by Marlène's family, just before being arrested. Today, the crooks have escaped and want the loot back. But a contractor has got permission to tear down the ruined inn and build an apartment building on the site, unless it's completely repaired within a week. When Marlène calls him, Gert abandons his planned week of holiday at sea to do the daunting job, helped by the mayor, Van Leemhuyzen and Octaaf. Alberto meanwhile rides through town on his motorbike, trying to get his career launched as a 'flying barber'.