It is Muriel Spark‘s centenary this year. The Edinburgh-born author’s most famous book was The Prime of Miss Jean Brodie a dark, acerbic tale set in Marcia Blaine’s, a posh school for girls. The pupils are corrupted by a certain teacher who inculcates the joys of classical ballet and cold cream. The pubescent girls are in thrall to the glamorous teacher whose lover, the teacher constantly tells them, fell on Flanders Field. In one of the most delightfully comic/absurd moments in the short novel, two of the schoolgirls write a love letter to the music teacher and sign it from Miss Brodie. It ends: “Allow me, in conclusion, to congratulate you warmly on your sexual intercourse, as well as your singing. With fondest joy, Jean Brodie”.

Olga Wojtas’s narrator, Shona, a former pupil of the imaginary Marcia Blaine’s, encounters the founder (a ghost, and mirage?) at her desk in the Morningside public library. Shona is forthright in her dislike of Spark’s tale of Miss Brodie, it having besmirched the name of the school, and she soon passes the Blaine test. Shona receives a mission to travel back in time to 19th-century Russia on a secret mission. Of course she accepts.

This mash up of Narnia, Harry Potter, Alexander McCall Smith, and Miss Marple in other hands might have been a time trip too far, but Wojtas’s tongue is firmly in her cheek. The culture clash of a contemporary fifty-something woman in the court of the tsars, clumping about in DMs under her crinoline, and talking about human rights to the incomprehensible serfs makes for much gentle humour. The reader is kept in suspense as Shona and her 21st-century attitudes clash with courtly protocol.

Although the book starts well, there are soon too many cups of tea and knitting nannies. Halfway through, it becomes wearying. The Spark/Brodie connection is also a bit of a red herring. There are slightly too many quips about the mysterious goings-on of soap dodgers west of the Gogar and assorted Scottish couthy-isms. The book is structured well and the reader is kept turning pages, but the secret mission rather drowns amidst a lot of carriage rides and formal balls. You keep imagining that Shona’s plainspokenness will set up more comedy moments than it actually does.