The author of The No. 1 Ladies' Detective Agency joins Canongate's laudable series inviting writers to reinterpret a myth, or, as Alexander McCall Smith describes it, ''a cloud based upon a shadow based upon the movement of the breeze.'' This is a wonderful exercise for authors and readers, so it's hard to begrudge McCall Smith his experimenting in Dream Angus, by mirroring tales of the Celtic god of dreams and love with modern stories. While some are lackluster, ''Is There a Place for Pigs There?'' (two people unite thanks to a doomed lab pig) and ''I Dream of You'' (a married couple find forgiveness after an affair) are indeed worth losing sleep over.