To Visit the Queen

To Visit the Queen (1998) (titled On Her Majesty's Wizardly Service in the UK edition) is a fantasy steampunk novel by Diane Duane. Its plot deals with the invention of nuclear weapons in Victorian Britain, thanks to the evil intervention of the Lone Power and the efforts of Duane's wizard feline adventurers to save the day.

It was a sequel to The Book of Night with Moon (1997). In its review, Publishers Weekly said, "Duane presents her usual felicitous mix of magical high adventure and humor, avoiding much of the preciousness that can infect anthropomorphic fantasy. Even those who don't fancy felines should enjoy this purr of a tale." Kirkus Reviews was somewhat less kind, criticising what it termed "a slow start" and "mind numbing details" in a book aimed squarely at the young adult market.

Cultural reference
The title To Visit the Queen is a cultural reference to the English rhyming poem known as "Pussy Cat Pussy Cat"; it is the second line of the poem. The British title On Her Majesty's Wizardly Service is reminiscent of the James Bond title On Her Majesty's Secret Service.

One element of the plot bears a similarity to Project A119.