The school year was over and the summer holidays were finally here. As usual, Mum and Dad were taking Jacob and Matthew to stay with their grandfather.
Grandpa Henry was the warden of a wonderful medieval castle, which meant he also lived there. The castle was always busiest in the summer, when many people came to visit and find out all about its history. Jacob and Matthew loved spending time with their grandfather and helping him out with all the little jobs that needed doing.
Even Grandpa’s name totally suited the atmosphere of the old castle. It sounded ancient and noble. The boys had even found out that the name Henry meant “ruler of the house”. Sometimes they joked that he was the “king of the castle”.
Since Grandpa Henry spent most of the day guiding tourists around the main parts of the castle, the boys had plenty of free time to explore the more remote areas of the castle complex on their own. And when Grandpa Henry had a little free time, he would come and join them.
One sunny morning, Matthew and Jacob went up to the castle attic. Behind a dusty curtain, they came across an old wooden trunk.
“Jacob, have you ever seen an old trunk like this before?” Matthew asked with a sparkle in his eyes.
“Yeah, in a pirate film! If there isn’t a treasure map inside, I’ll be disappointed,” replied Jacob, and they excitedly set about opening it.
As Matthew struggled to open the heavy lid, they both caught a glimpse of something glinting inside.
“Woah, treasure?!” Jacob exclaimed, leaning in to get a closer look.
Matthew reached in and pulled out an old key. It was slightly rusty in places and was marked…