In the second story in the series, "Valley of Dreams", Tweel's species is revealed to be known as the Thoth: Tweel shows his human companions an ancient Martian mural portraying his species surrounded by what are recognizably ancient Egyptians. When one human describes the mural as resembling the Egyptian god Thoth, Tweel's response is "Yes! Yes! Yes! Thoth! Yes!"; the humans then realize that Martians - collectively known as "Thoth" - visited ancient Egypt, where they gave humans the gift of writing and were perceived as gods.