Robot Trains - Season 1 - Eps 23: Kay and Duke
While Kay and his friends are searching for the virus inside Duke's memories, they find Duke's memory of the day before the opening ceremony of the Intercontinental Railroad, where a virus infected Duke's system and turned him evil. They now know that Duke was a victim of the virus. Fighting the mutant virus monsters, Kay and the friends get closer to the central part of Duke's engine.
About Robot Trains

Title: Robot Trains
First Air Date: 2015-02-26
Last Air Date: 2019-05-19
Status: Ended
Rating: 5.7/10 (from 3 votes)
Language: KO
Seasons: 2
Total Episodes: 84
Network: Unknown
Genres: Animation, Kids, Action & Adventure, Comedy, Sci-Fi & Fantasy, Family
Production Companies: CJ ENM, Union Investment Partners, Woori Investment Co.
Synopsis
Set in the "Train World" where all citizens are trains. However, among the residents there are special trains that can transform into robots, the Robot Trains! Featuring our 5 train heroes, with special powers: Kay, Alf, Duck, Selly and Victor - and their exciting adventures. Can the Robot Trains save the village from the evil dark forces that be?