Hedry Mária - Felfedezők Széplakfalván

What is a found piece of pottery for, how can an observatory and a time machine be secretly manufactured in a newly discovered cave, who are the dancing witches at the castle ruin at night?
The teenage brother and sister, Iván and Míra, i.e. Ivi and Mimi, go on a summer vacation to a village they think is boring - but it seems that there is nothing there... We can follow their fantastic adventures in this fun, humorous and exciting novel, which is full of amazing with twists, mysteries and understanding, wise love.