As we are told in the book, clock-jacks, or jaquemart, are mechanical human figures that strike the time on a bell. Bellairs put this pair of clock-jacks in his version of Stillwater, Minnesota, but Gog and Magog also make their home in Michigan. About one-hundred miles west of Marshall in Dearborn is the Henry Ford Museum and Greenfield Village. It is here that both Gog and Magog strike the quarter-hour at the Sir John Bennett Jewelry Store. The clockwork tolled each quarter hour from 1846 to 1929 above the Sir John Bennett Jewelry Shop in London, England. When the building was about to be pulled down, Ford had the original five-story building trimmed down into a smaller two-story building. Except for the clockwork and a few parts of the building front, the building itself and its interior were created in Greenfield Village.

What or who Gog and Magog were is somewhat confusing, since from their two references in the Bible one could label them human, supernatural entities (giants or demons), lands or cities. In the Bible (Ezekiel 38:2-3) Gog was King of Magog, a northern land whose fierce hordes eventually invaded Israel. Later Gog and Magog symbolize the enemies of the Kindgom of God (Revelation 20:7-8).

As giants, they are the traditional guardians of the City of London.