Unexploded Unclear Bomb

 is a Sunless Sea Random Event.

Story description
''The silt half-covers a gleaming copper sphere, studded with spikes. A deep red light flickers continuously from within its central chamber. Your zubmarine's lights fail and darken as they glance across the shell.''

Trigger conditions
This event is triggered by zailing into an Unexploded Unclear Bomb on the Unterzee floor.