While Juniper and Alex are away visiting Abbe Breuil, the baddies, having followed the crumbs left behind by J & E, arrive at the Chateau in search of the paintings. They have drawn the conclusion that the paintings are hidden behind 16th C masonry on one of the lower levels, immediately above the grotto (of which they are unaware).
The decide to use explosives, stolen from the local criminals (a bunch of bad boys pushed out of Munich by the 1929 putsch).
Unbeknownst to them, they set off the explosives shortly after Juniper and Alex return to the grotto with a student of the Abbe (Jean-Paul) and permission to enter.
The explosion blocks the doorway and they fear they are trapped. (reprise of the prologue). However, the explosion exposes a fault in the back wall which leads to an extension of the grotto. Inside are cave paintings to rival Lascaux or Font de Gaume.
Above, the baddies break through the shattered masonry to find... a mummified body, a leather satchel and a much-thumbed and crumbling English Vulgate Bible. Some poor soul had somehow been immured in the 16th C.
They take the Bible, hoping to make a few pounds from it, and leave.
Down in the cave, Juniper sees the dim light above through a crack. She manages to wiggle up through the rock into the upper chamber, in time to see the baddies walking across the meadow below.
She calls down to the two in the cave, promising help but swearing them to silence about the grotto. She hikes back to the troglodyte village to find the passionate prehistorians they had previously met. They agree to rescue Alex and Jean-Paul, but keep the grotto secret.
