Jamie and Claire use Claire's medical knowledge to devise a scheme to stop a wine deal which could fill the Prince's war chest. When Claire learns Jamie has gone back on his word, the couple is met with dire consequences that will forever change their lives.
In order to deprive Charles Stuart of the funds for his invasion, Claire and Jamie devise a scheme which will prevent him from selling a consignment of wine, first by feigning smallpox on the boat carrying the wine and then by robbing the remainder. In both cases St. Germain is among the losers. Fearing for the future existence of her husband, Frank, Claire asks Jamie to postpone the duel with Black Jack Randall for a year and is angry when he breaks his word.
- The episode title is a reference to the poem "To a Mouse" by Robert Burns: "The best laid schemes o’ Mice an’ Men / Gang aft agley, ..."
- Chapter 23 of Dragonfly in Amber is called "The Best-Laid Plans of Mice and Men...", an anglicized version of the lines from Burns' poem.