When a light thief steals all the lights from Axle City, Blaze is outfitted with speed lights so he can chase after her and retrieve them. Elsewhere, Crusher tries to prove he can handle himself in the dark with disastrous results.
One night in Axle City, Blaze and his friends are having a special night race at the park. Even though it's dark out, the track has special lights on so they can race. Together, they have one more lap and continue racing.
Not far, a kangaroo is stealing lights from the various street lamps from a road when she spots the track and its lights. Getting an idea, she takes all the lights just as the Monster Machines are finishing the last lap, causing them to crash into things and go out of control. AJ then sees the kangaroo stealing all the lights, and Blaze realizes she's a Light Thief before she disappears.
The Monster Machines attempt to go after the light thief, but without any lights, they cannot see where they're going. Gabby installs a special battery into Blaze which makes him light up and see in the dark. She says they're his new speed lights, making him a Light Rider, and goes off to chase the Light Thief as Blazing Amazing plays.
The Light Thief continues to steal lights from a street and a long tunnel, which Blaze goes through to follow her. Not even some time into the tunnel though, he hears a weird clucking sound, which happens to come from a group of pesky night chickens which peck him all over and chase him out.
Retreating from the tunnel, AJ realizes the tunnel is full of night chickens which love pecking them. Blaze points out the night chickens only come out when it's dark, so if they send enough energy from the battery into the speed lights, they Blaze can shine bright enough and chase the chickens away. Blaze succeeds with help from the viewer; whenever a chicken appears, he makes his speed lights shine bright and scares them off. He and AJ make it out of the tunnel and go on, singing Light in the background as they test out their speed lights.
Meanwhile, Pickle is enjoying the dark, using a flashlight to find many things, even Crusher who is with him. Crusher bets he doesn't need a flashlight to find stuff in the dark, and thinks he found a sandwich, only for it to turn out to be a shoe, and he's grossed out.
The Light Thief steals more lights, causing a truck to drop his watermelons before Blaze catches them. He and AJ chase the Light Thief to the construction site, where she steals the lights and inadvertently activates the machines, causing them to block Blaze with metal pipes. AJ determines they need a laser with a really strong light to cut through the pipes, and Blaze turns into one to do so. Blaze cuts through all of them with help from the viewer, and after getting free, he hurries off to catch the light thief once and for all.
Meanwhile, Pickle finds more stuff with his flashlight, and Crusher bets once again he doesn't need one. He finds something which he thinks is a bowl of spaghetti, but it's really a mop, disgusting him.
The Light Thief comes to the carnival and steals all the lights, just as Blaze confronts her before she escapes. Blaze cannot see where she went because of how big the carnival is, so he is greeted by Gabby and the Monster Machines, all outfitted with speed lights to help out. Increasing their light energy, Blaze manages to find the Light Thief with the viewer's help, and they chase her until Blaze traps her in a barrel.
Blaze confronts the Light Thief, asking her to give back all the stolen lights, but she refuses and explains why: she's afraid of the dark. Blaze reminds her it's okay to be afraid of the dark, Gabby adding everyone's afraid of the dark from time to time. Blaze then says she doesn't need all the lights to feel better, and AJ places a small light on her hat to help her out. The Light Thief isn't afraid of the dark anymore and apologizes for stealing all the lights, but putting all the lights back will be a big job. So Blaze uses his Blazing Speed to restore all the lights, as a reprise of Light is heard.
Making it back to the race, the Light Thief puts the last light back, and the Monster Machines decide to finish their race. Blaze then gets an idea: since they all have speed lights, he thinks it would be fun to race in the dark and turns the track into a Light Riders speedway, with neon lights. The Light Thief starts the race and the Monster Machines have fun, letting their speed lights light the way. Blaze jumps at the camera, ending the show.