Master Card depiction of Lost Zem in Ao no Kiseki.

Lost Zem (ロストゼウム), also known as the Great Black Mallet (巨の黒槌), is one of the Sept-Terrion and is the treasure governing over Earth. In contrast to the Ark Rouge, which has dominion over souls, the Lost Zem has dominion over physical bodies.


Lost Zem was originally situated in the land of Erebos (Erebonia), where it was worshipped by a civilisation now known as the Gnomes. Together with Ark Rouge it forms the Great One.

The Chief of the Gnomes can command the Lost Zem to boot into the Sacrament Program.

The Holy Beast sworn to protect Lost Zem is Argres.


  • 'Lost Zeum' is a portmanteau of 'lost' and 'seum' from 'museum' according to Toshihiro Kondo.[1]
  • Zem means 'earth' in Czech and Slovak.[2]


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