Brothers in Arms

S3 E3: Under orders, the Musketeers defend Louis' traitorous brother Gaston after he slaughters a band of veteran soldiers in a Paris tavern. The heartbroken owner, Christophe, demands justice - but the preoccupied King welcomes his formerly exiled brother home with open arms. As tensions ignite and secrets spill, Treville crosses a dangerous line and the Musketeers are forced to choose between their royal duty and fellow soldiers. Meanwhile, Feron and Grimaud spy a kindred spirit in Gaston.