Evening-length story ballets are box-office fodder—or would be if ballet were only to oblige. But, as Balanchine famously observed, the idiom doesn’t do mothers-in-law, much less the “murder, sex, and unsuitable lovers” (as biographer Antonia Fraser has it) that embroiled Mary, Queen of Scots. Nevertheless, she is the subject of a new full-length work by the Scottish Ballet. The enterprising company has doubled up on everything. Michael P. Atkinson (Sufjan Stevens’s arranger for Justin Peck ballets) and Mikael Karlsson (composer of bouncy scores for several Alexander Ekman productions) provided the music. Resident choreographer Sophie Laplane counted on opera director and dramaturge James Bonas to smooth out the plots and counterplots on which the intrigue depends. And the narrative features two heroine-villains: Queen Elizabeth and her wayward cousin. As the ballet’s anchor, these women are its best hope. Mary, Queen of Scots premiered last year at the Edinburgh Festival. —Apollinaire Scherr