Why is it called Archer: 1999?

Season 10 will be set in Archer’s subconscious version of space, based on his 1970s idea of the future and will be titled Archer: 1999. Title reference to ’70s sci-fi TV series Space: 1999.

Where does the Archer take place?

Archer follows the exploits of eight dysfunctional secret agents and supporting staff of the International Secret Intelligence Service (ISIS), a fictional New York–based intelligence agency.