Robin Hood 1x09 "A Thing Or Two About Loyalty"

Castle scientist Lambert has invented explosive black powder. Realising that it could become a lethal weapon in the wrong hands, he hides his ledger detailing the secret formula.

Not even Lambert's friendship with Gisborne can save him from the wrath of the Sheriff who tortures him until he speaks.

In order to discover the ledger's whereabouts, Much gets himself arrested. But the Sheriff throws a spanner in the works by appointing Much Earl of Bonchurch as a ploy to spy on him.

As Much is shipped off to his new estate, Lambert reveals the ledger's whereabouts to Robin.

Elsewhere, Much falls head over heels for servant girl Eve, unaware she's the Sheriff's spy. However, Eve betrays the Sheriff by giving him false information about the ledger's location.

Discovering Robin has salvaged the ledger and knows the location of the black powder, the Sheriff and Gisborne endeavour to move it. However their, attempts are thwarted when Robin blows the entire lot up.

Against Djaq's wishes, Robin throws the ledger into the fire. But when the gang aren't looking, she salvages it from the flames. Unknown to Djaq, Robin has seen her...

when Eve told the sheriff that Robin had hidden the ledger in the barrels of powder, off they raced to recover it. But they didn't consider for even a moment that they had hidden the powder in a safe place, and Robin didn't know where it was.