LEGO Hidden Side Paranormal Intercept Bus 70423. Enter the Hidden Side. Download the LEGO® Hidden Side™ app and point your phone at the school bus model to bring it to life. Play with the model to see what happens in the app. Solve mysteries, find items, catch and collect ghosts and take on boss ghost Spewer. Two possessed workers keep attacking and a monstrous haunted toilet fires brown tiles. Deploy the control station and extend the side cannons for ghost-catching action, or create your own ghost-hunting adventures with the brick-built model.