Rock 'n' Roll is the 88th episode of Thomas and Friends.
Skarloey tells Rusty the railway looks drastically different since his return from the works because of the fixes to the lines. Rusty explains that the manager had planned to give Skarloey a surprise upon his return. Later that day, Rusty warns Skarloey that there is still a damaged piece of line just outside the first station and worries that Duncan, with his habit of "rock 'n' roll," will derail there. Duncan overhears the engines' conversation and demands to know why they are talking about him. Rusty attempts to warn him, but Duncan dismisses the warning and rudely calls Rusty a smelly diesel.
Duncan collects his coaches and arrives at the station where James is waiting for him. When Duncan explains his grievances with Rusty, James tells him of the time he supposedly sent Diesel packing. Filled with admiration and unaware James was bragging and is not always honest, Duncan becomes more reckless and begins to "rock 'n' roll," which ultimately causes him to derail when he reaches the damaged track Rusty warned him about.
Rusty is sent to help, but initially refuses. Skarloey expresses his disappointment that Rusty is just going to leave the passengers stranded. Upon being reminded of the passengers, Rusty sets off with some workmen who work alongside the passengers to lever Duncan back onto the rails. Duncan finishes his journey without any further mishaps, and later that evening, he apologises to Rusty and asks if they can be friends. Rusty agrees and promises to mend the damaged line in the morning.