Reign 3×07 “The Hound and the Hare” (Mid-Season Finale) – When Prince Don Carlos (guest star Mark Ghanimé) of Spain visits France, Mary (Adelaide Kane) uncovers a dark secret he is hiding and enlists in Catherine (Megan Follows) to advise her on how to handle. When Gideon (Ben Geurens), the new ambassador from English court arrives, suspicions arise about what his true intentions are, while Bash’s (Torrance Coombs) pursuit of the mysterious killer comes to a head at Greer’s (Celina Sinden) tavern. Rachel Skarsten, Charlie Carrick, Rose Williams, Jonathan Keltz, Toby Regbo, Craig Parker and Anna Popplewell also star. Anne Wheeler directed the episode written by Bo Yeon Kim and Erika Lippoldt (#307). Original airdate 12/4/2015.