Sat, Jan 6, 1973
A huge storm hits the small mining village. On the coming day a few village children discover the entrance of an old mine, which was buried for a long time. Despite the explicit prohibition of local elders two boys go down to the mine. An old man, when he learns this, distracts them and calls Border Guards to blow up the entrance. Meanwhile, one of the boys' little brother goes missing, leaving behind only a drawing, that shows he gone down to the pit.
Sat, Jan 13, 1973
Something very suspicious of Lacó with old Lipót Gasch. He has the Border Guards blow up the entrance to the resurfaced mine, and his niece shows up with 4 huge suitcases. Lacó decides that from now on the house of the old man will be kept under constant surveillance. Things are made more difficult by the fact that a relative of Pöcök arrives from Budapest, with whom his parents do not allow him to go anywhere.
Sat, Jan 20, 1973
No one goes to collect Tivadar at the bus stop, but he gets a lift from Irma to Lacó's home. Although the guys want to completely ignore the relative from Pest, he has insider information about the mysterious car, as he was sitting in it. It soon turns out that he is actually a normal guy, so they let him join to their investigation. While Pöcök develops his radio at home, Lacó and Tivadar go around the village to get information about the old Lipót Gasch.
Sat, Jan 27, 1973
When Pöcök climbs the radio tower to get a better signal, he looks through his binoculars into old Gasch's yard, where he sees an unknown man with suitcases. When he tells the boys they try to get in there but they fail. It's time to call Corporal Pirosfej for his help, but even they get into the yard, can't see any suspicious. When Pöcök returns to the tower, he witnesses the stranger again, this time descending into a well.
Sat, Feb 3, 1973
While Lacó and Tivadar climb down into the well, Pöcök stays outside to get help if needed. The well leads to the old mine, where Lipót Gasch and the stranger are about to transport contraband across the border, underground, a mile away. The boys get caught, but instead of calling help Pöcök goes to free them himself, and they just get in bigger trouble all together. But things eventually take a turn for the better when border guards show up and apprehend the gang, thanks for the twins who go from neglected to heroes of the day.