What are some of the recurring symbols and motifs in 'El Eternauta' and what do they represent?

Recurring symbols include the abandoned house, the ‘unknown’ itself, the recurring figure of the ‘man in the shadows,’ and the use of light and darkness. The house represents the repressed past and hidden truths. The ‘unknown’ symbolizes the dangers of unchecked power and the loss of innocence. The ‘man in the shadows’ embodies the surveillance state. Light and darkness represent hope and despair, knowledge and ignorance.