In his new role of thriller-writer, Luke Allan threatens to eclipse the Luke Allan of 'Western' fame. Blue Pete: Half-Breed, The Blue Wolf and The Lone Trail are cow¬boy stories which remain evergreen in the public memory, but The Man on the Twenty- Fourth Floor, which appeared last season, and The Ghost Murder are thrillers that must steal much of the thunder of his earlier successes. The Ghost Murder tells how a bogus invitation sent eleven ill-assorted people to a gloomy house on a desolate island: how murder was committed, and how any one of those present might well have struck the death blow. It is an excellent thriller in which the element of mystery is admirably sustained.