DRAMA A repeat worth flagging - Flatline was a tense and startlingly imaginative episode in Peter Capaldi's first series. Written by newcomer Jamie Mathieson and directed by Line of Duty's Douglas Mackinnon, it dares to explore the dimensional aspect of the acronym Tardis (Time and Relative Dimension in Space). It pokes fun at the Time Lord, trapped in a shrinking police box. while monsters cross over from a 2D plane into our 3D reality. Kudos to the art department for their superb effects work and nods to graffiti artist Banksy.