The Lab Rats get their first mission to stop Davenport's hi-tech super fast train from speeding out of control. Leo sneaks along, but when the Lab Rats discover he accidently discarded the braking system they were supposed to install, they must improvise a way to stop the train before it crashes into a nearby town. Meanwhile, Tasha is given her big break at the TV news station when her boss asks her to cover the runaway train.
