The Doctor is putting out another fire from a bunsen burner on the console. He's impressing Amy with his fire extinguisher — eighty times more times foam than normal extinguishers — a gadget he modestly says he invented. When the TARDIS arrives in Echo Sphere (a self contained unit, a protective shell for the inhabitants sealed within their planet), the sound of the TARDIS arriving reverberates around the Sphere. With its ever-increasing volume, the noise distresses the inhabitants — peaceful, green, bird-like creatures known for their occasional, very quiet, gentle songs.