Sonar Square

A sonar square is an electrical device invented by Jenny Peter, and built by Lily. It looks like a steel square, and is used to fix sonar if it isn't working. It can also fix the internet. It is first seen in The Closed Doors.

Appearances

 * The Closed Doors
 * A Sight to See
 * Chaos Fallen
 * Sunburnt
 * Her Last Tears