A creation by Jessica Whitwell, it totally imprisons a demon's essence and causes them extreme pain if they touch the orb. It can shrink to nothing and is mainly used to torture demons (such as Bartimaeus) who are trapped in the Tower of London. It was once threatened to put Nathaniel in a Mournful Orb, proving that it can be used on humans as well.
FunctionEditThe Mournful Orb is part cage, part torture device. It is composed of a nexus of blue lines that burns a demon's essence on contact. It is also impossible for a demon's essence, and therefore the demon, to leave the orb unless the orb is deactivated or interrupted by something that works against magic, such as an iron ring. Summoning a demon who is in a mournful orb is impossible. A mournful orb can be made to expand or contract on command, making them effective torture devices on any demon unfortunate enough to be inside.
Based on the description, the Mournful Orb is likely a more sophisticated form of a Nexus Barrier.