Echo... echo... hello... hello! Lumina is shouting into a big cave and the cave is being cheeky and shouting back at her! She’s giggling at the silly sounds and shiny reflections. A) The Story of the Bat Who Used Sound to See in the Dark. B) You want to send a secret message across a room! Do you use a super-bright torch or a super-loud whisper? C) Let's make silly echoes with our voices!