When the bulb in the Adventure Bay lighthouse goes out, Ryder and the PAW Patrol battle the clock and thick fog as they try to fix the light in time to get their good friend Cap'n Turbot back home safely.
The episode begins with the pups preparing for a sleep-out under the stars. Zuma is busy enjoying the bag of treats the pups have with them. As for Chase, he is having a little trouble with his sleeping bag, as it keep rolling back up from the free end he doesn't have his weight on. It only gets worse when one of the other pups knocks into him when calling dibs on the final treat offers, wrapping him up in his own sleeping bag, leaving him disappointed at the sleep-out being ruined for him, while the other pups laugh.
On the Lookout's balcony, Ryder watches the sunset, and the light from Cap'n Turbot's lighthouse on Seal Island come on. However, the light seems to be flickering and faltering. Concerned, Ryder checks through the Lookout's periscope, and watches as the light burns out completely. Worried, he calls Cap'n Turbot to let him know, but the good captain is currently out at sea on the Flounder when he gets Ryder's call. Worse, a heavy fog is rolling in, and without his lighthouse's beacon, Cap'n Turbot cannot even get home to Seal Island to replace it. To make things more problematic, Turbot knows that the MS Princess Maria cruise ship is due through Adventure Bay in an hour, and without the lighthouse, the ship could run aground on the rocks near Seal Island.
After the Captain has a moment of amnesia and forgets he had already called Ryder when he decides to call them and let them know, Turbot panics and gets himself stuck in a bucket. Ryder assures that the PAW Patrol are on their way, and Turbot walks away to continue his own business with a cheerful whistle.
As the pups are summoned to the Lookout, Chase is left to try and slither after them since he was still stuck in his sleeping bag, then hop after them into the elevator. Marshall gives the pups a good laugh after he sneezes up some feathers, and the pups are given their orders upon reaching the top: Ryder will head out with Zuma and Chase riding in Zuma's hovercraft to Seal Island and attempt to use Chase's light on his megaphone to substitute for the lighthouse's light until Cap'n Turbot can return to replace it, and prevent the Princess Maria from hitting the rocks. The other pups will need to try and stay awake in case Ryder needs backup.
While the pups do what they can to stay awake and not fall asleep, such as playing Marco Polo, Ryder, Chase, and Zuma find their way to Seal Island blocked by Wally the walrus. Despite their attempts to warn him that there is an emergency they need to get to, he only lets them pass once they give him a treat. When they reach the lighthouse, the door is locked, and Cap'n Turbot has the keys with him personally back on the Flounder. Worse, the Princess Maria is now visible heading straight for Seal Island. With time running out, Ryder suggests having Chase fire his net under an open window for Ryder to use as a cargo net to climb up and into the lighthouse. Once inside, Ryder unlocks the door for Chase and Zuma, and they head for the top. When they get there, the Princess Maria's captain contacts them on the radio asking about the lighthouse's beacon. Ryder responds, and Chase gets his megaphone's light on just in the nick of time, allowing the captain and his crew to steer the Princess Maria clear of Seal Island. The captain sends his thanks and blows the ship's horn in gratitude, and Cap'n Turbot soon arrives home to replace the lighthouse beacon's bulb and thank Ryder for all his help.
Back at the Lookout, the other pups are about ready to doze off when Ryder, Chase, and Zuma return. Marshall speaks for all of them at how they stayed up in case Ryder needed them, and Skye can't wait to hear what happened. As Chase and Zuma let off tired yawns, Ryder goes to retrieve some sleep-out snacks for the pups to have as he tells them everything. When he returns, all the pups have fallen asleep, so he leaves the treats for them to have when they wake up. As the other pups sleep soundly, Ryder and Chase exchange a warm smile before dozing off themselves, Ryder wishing his pups goodnight as the camera pans upward to the star-filled sky.