When a Spanish general, Tariq Alaman (Colin Salmon), offers to hand over the formula of a unique and deadly gunpowder in exchange for help rescuing his kidnapped daughter, the Musketeers find themselves tangled in a complex web of political trades with the Spanish. Their mission is further complicated when Porthos (Howard Charles) is captured by Spanish agents.

Meanwhile, when the dauphin becomes seriously ill, Constance (Tamla Kari) takes matters into her own hands and risks everything to save his life.

The Musketeers: ‘The Good Traitor’ airs on BBC One Friday 16th January at 9pm.

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(C) BBC/Dusan Martinek

Watch the preview clip & episode 3 trailer below…