Forged in Fire S08E12 - San Mai Mystery

Four smiths are blindsided when they must choose from a selection of mystery steel to create san mai blades. However, that isn't the only unknown. The clock will be off, leaving the smiths to rely solely on time calls for guidance. After a surprising round of tests, the last smiths standing will select between two weapons to forge at home. Which smith will uncover the secret to forging a weapon worthy of $10,000 and be crowned Forged in Fire Champion?