This reminds me of Peter Watts's novel <Blindsight>. Two captured "Scramblers" (the highly intelligent alien without self-consciousness) managed to communicate

This reminds me of Peter Watts's novel <Blindsight>. Two captured "Scramblers" (the highly intelligent alien without self-consciousness) managed to communicate with each other in a way defying all human analysis, even with human knowing what they are saying (the plain text).