ANDREW: [bringing a very large and heavy book] Here you go.
CHRISTOPHER: Holy mother. This is the monolith from 2001.
Christopher is referring to the 1968 science-fiction film 2001: A Space Odyssey, directed by Stanley Kubrick, and partially inspired by a short story called “The Sentinel” by British sci-fi author Arthur C. Clark, who co-wrote the screenplay.
The film features a mysterious flat black monolith which seems to have affected human evolution from prehistoric times by somehow artificially speeding up intellectual development. The Compact Oxford English Dictionary is nowhere near as as large as the monolith in the film, but has similar intellect-stimulating properties. The writer may have referenced the film as it was now 2001.
On release, 2001: A Space Odyssey received mixed, or even polarised, reviews from critics, but gained a cult following. It went on to become the #1 film of 1968, and won the Academy Award for Best Visual Effects. It is now regarded as one of the greatest and most influential films of all time.