Duncan and the Old Mine

"That looks like a good place for an adventure!"

- Duncan

Duncan and the Old Mine is the twentieth episode of the ninth season.

Plot
Duncan is looking forward to taking holidaymakers to see the Culdee Caves when his job is given to Bertie instead. Mr. Percival wants him to deliver coal trucks to the transfer yards with Rusty as the machines at the coaling plant have broken down. On his way to the coal mine, Duncan sees an old line leading towards some bushes and, ignoring Rusty's reminder that they have work to do, he goes down the old line which leads to an old mine entrance. Carelessly, Duncan crashes into a roof support, causing the entrance to collapse behind him. Duncan carries on into the mine until he hits something, which he thinks are buffers - until he hears a squeaking noise and realizes that he ran into some coal trucks. Pushing the coal trucks, Duncan finds that the mine shaft was actually a mine tunnel when he arrives at a bordered-up exit, and then, he pushes the trucks out of the mine. Rusty, who had being looking for Duncan, finds him with the coal trucks, so they take it down to the Transfer Yards where Mr. Percival tells Duncan that he must think clearly when he wants to have another adventure.

Characters

 * Thomas
 * Duncan
 * Rusty
 * Mr. Percival
 * Mighty Mac (cameo)
 * Bertie (mentioned)
 * Sir Topham Hatt (mentioned)

Locations

 * Transfer Yards
 * Rheneas Viaduct
 * Middle Station
 * Culdee Caves
 * The Coaling Plant (mentioned)
 * Skarloey Coal Yard (mentioned)

Trivia

 * Going by production order, this is the twenty-first episode of the ninth season.

Goofs

 * Rusty was referred to as female in the first American narration.
 * In the scene of the trucks approaching the boarded-up exit, after they stop a shadow moves across one side of the door.
 * The mine that Duncan went into was not really a mine. If it was a mine, it would not have come out on the other side of the mountain.
 * The points switch back to Rusty's line after Duncan went onto his line. They also seem to switch for Duncan as well, as he was supposed to be on Rusty's line, and he went onto the other sealed-off line.
 * When Rusty and Duncan arrive at the Transfer Yards, the truck behind Rusty is derailed.
 * Some wires can be seen on Duncan's cab when he pushes the trucks.
 * A brakevan should have been added to Rusty's train.