Space scientist Maggie Aderin-Pocock discusses John Wyndham's sci-fi novel Chocky, in which an 11-year-old boy develops an unusual relationship with what his parents suspect is an imaginary friend. Record producer William Orbit selects Tom Stoppard's Rosencrantz & Guildenstern Are Dead, an alternative view of the events of Shakespeare's classic Hamlet, while Harriett Gilbert picks out The Trick Is to Keep Breathing, by Janice Dalloway