The presenters look back at some of our amazing dens from series one and two, seeing how they have been enjoyed and finding out how they changed the lives of the young Dengineers. Lauren revisits the survival, art, Hollywood cinema and DJ dens.

Joe and Lauren get the help of experts to design dream dens for children. Helena is 11 and an only child. She loves star-gazing, wants to be an astrophysicist when she's older and is passionate about girls getting into science. She lives above her mum and dad's bookshop where they often work seven days a week which means she doesn't get the chance to get out and look at the night sky! Helena needs a den to help her reach for the stars and fulfil her science dreams.