Viking Edition: Competitors march into a dry moat where they resurrect old swords and forge them into a Viking Seax. (S4, ep 23)
Ultimate Champions Edition: Five champions return to the anvil, with the final two competing to craft the finest Tai Chi sword. (S4, ep 22)
Knights Templar: The smiths must forge together rusty chain mail and high quality steel to produce weapons used by the Knights Templar. (S4, ep 21)
International Championship: Four of the top smiths from around the world compete in an international championship, with the best two crafting a Spadroon in the final. (S4, ep 20)
The Yatagan: The smiths are tasked with turning a rusted 1971 Mercury Cougar into their signature blades, before creating an elite military weapon known as the Yatagan. (S4, ep 19)
The Kpinga: After layering a complex Damascus pattern in their signature blades, the remaining competitors recreate a three-bladed African throwing knife called the Kpinga. (S4, ep 18)
The Kampilan: Four bladesmiths head to a scrap yard to create their signature blades, then recreate a fearsome battle weapon known as the kampilan. (S4, ep 17)
The Shamshir: The contestants get to work on a unique bowie knife in the first round, before two will go on to craft a deadly sabre called The Shamshir. (S4, ep 16)
Redemption: Four previously eliminated bladesmiths return to the forge for a shot at redemption, but they face a challenge more difficult than they could imagine. (S3, ep 16)
Tabar Shishpar: Four more bladesmiths head into the forge to prove they have the mettle to master metal. (S4, ep 15)