The Splinter of Glass is a play written by Miss Maxwell-Perry, the new English teacher at St. Ronan’s, in Susan’s Trying Term. It is based on Hans Andersen’s Snow Queen. The leading role of Kay is given to Gabrielle Gascoigne and the part of Gerda goes to Susan’s friend Elizabeth Rogers. The play is described as poetical in some parts and "screamingly funny" in others. On the night it is performed, The Splinter of Glass is attended by influential friends of Selina Gascoigne’s: Lady Harrington, Julian Barwith and Tony Cassel, the latter two being producers. Mr. Barwith is so impressed by the play that he decides to produce it for a television broadcast. He wants to transport the play to London but is convinced by Miss Phillimore, the head mistress at St. Ronan’s, to film the play at the school. The play is broadcast live on the last day of term.