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.

Joe and Lauren get the help of experts to design dream dens for children. Claire House Children's Hospice is a BBC Children in Need-supported charity in the Wirral. They do an amazing job looking after children with life-limiting conditions as well as providing much needed care and support to their families. In order to help more children than they can at the moment, they are opening a new site in Liverpool and that is where the Dengineers come in. With the help of all our on-screen designers, and the Blue Peter audience, we are going to build an amazing den for the children and their siblings to enjoy, where they can make happy memories. This is the biggest build ever attempted by the Dengineers!