Stuart Paterson (creator of a barrowload of much-loved children's theatre works, to say nothing of his many stage dramas and screenplays for adult audiences) seems to be locked in a competition with David Greig for the title of "most prolific dramatist in Scotland".

Cars And Boys, Paterson's latest play for adults, was written ­especially for the Dundee Rep ensemble, and it shares some of the dream-like ­qualities of his award-winning work for children.

The drama's title alludes to the two major interests in the early adulthood of Catherine, a self-made businesswoman, who eschewed formal education yet went on to build a successful road haulage company nevertheless. A veritable human powerhouse, Catherine's breeze through life has been halted rudely by a paralysing stroke.

The play takes us into the dualistic world the businesswoman now finds herself in. Uncomfortably dependent on medical staff and family members, the brutal physical reality of her condition gives way to her subconscious, in which two would-be lovers from her past come with promises of romance on the other side.

Director Philip Howard's production is blessed with an excellent central performance. Ann Louis Ross (deserved winner of the Best Female Performance gong at the 2012 Critics' Awards for Theatre in Scotland) finds herself in another role which fits her like a glove. Unable to hear even an indirect reference to Tony Blair (who she rages against as a "war criminal"), her Catherine is a powerful and paradoxical combination of Sixties-style radicalism and Thatcherite individualism.

However, despite both Ross's lovely performance and some nice poetic and comic writing, both play and production contrive to disappoint. As the piece flits back-and-forth between Catherine's rudely interrupted life and the ghosts which populate her subconscious, it fails to generate any real sense of dramatic momentum.

If the play feels static and (at just 85 minutes) overlong, director Philip Howard's dramaturgical innovations (such as a sudden procession of well-wishers bearing gifts for Catherine) do not enliven it. Likewise Lisa Sangster's set; her quasi-abstract combination of elements - hospital, road and forest - founders, in both visual and atmospheric terms.

There are also difficulties in dramatic atmosphere in Pirates And Mermaids, the modest touring show by promenade and site-specific theatre specialists Poorboy. The show can be adapted for outdoor or indoor performance. When I saw it at the Woodend Bowling Club in Jordanhill, it was played in the club's bar, on account of the typical inclement Glaswegian weather making itself felt.

A solo piece, it is performed by engaging American actor Jeremiah Reynolds, who has nothing by way of set or props save for a smartphone. Reynolds plays a Scots-American, resplendent in Highland dress, who is caught in a painful trans-Atlantic romance.

The character's stories and reminiscences speak pertinently to the attachments, misunderstandings and resentments embedded within the relations between Scots and the Scottish diaspora.

However, as we struggle both to see the images the character displays on the small screen of his smartphone and to hear the audio he plays on its tiny speaker, one can't help but feel that Reynolds is being asked to do too much by himself. In its indoor incarnation, at least, the piece lacks sufficient theatricality to be anything more than a pleasant storytelling performance.

Find tour details for Pirates And Mermaids at: thebellrock.org