博客來1923 saw the performance of what is probably his most important full length play, The Glen is Mine. This work has good characterisation and a strong theme, the future of the Highlands: are industry and progress preferable to the destruction of the old Highland way of life? The ending, however, shies away from a bold resolution and opts for a safer, more sentimental conclusion.
The romantic comedy The Treasure Ship (1924) with its background of the salvaging of treasure from a Spanish galleon supposedly sunk in Tobermory Bay, was followed in 1925 by The Lifting (an extension of the one act The Change House), full of irony and coincidence, set in the south of Mull near Lochbuie, set in the period of the 1745 Jacobite Rising. It demonstrates the honour and decency of the hero Iain in sacrificing his life to protect the friend whom he had inadvertently implicated in the killing of an ＂enemy＂ before the beginning of the play.
