A man speaks into a camera. He says nobody should watch this. He explains that he’s at a lab, and he’s going to explain what is happening as best he can. His name is Rassmussen on the Le Verrier Space Station.
Cuts to a group of soldiers. Introduces some mean named Chopra, Commander Nagata, and Deep-Ando. They quibble, but tney’re own mission to find out what’s going on. There’s also a grunt, 474. They’re the rescue true, and the footage comes from their personal cameras. They came to rescue Rassmussen. Rassmussen warns anyone watching that their lives may depend on paying close attention.
The rescue team moves through empty corridors. Rassmussen says there was no crew left, but there were strangers. Those strangers are Clara and the Doctor. He rescue team pulls their guns on the Doctor and Clara. The Doctor flashes his psychic paper. They believe he is a stress assessor. They explain that the station went silent 24 hours ago and they’ve come to find out why. Nagata puts them under her command.
The Doctor examines the ship believes it’s been dead for a long while.
474 says there are eyes in the sky. He tries to pet Chopra. When Chopra swats his hand away, 474 responds as if it’s a physical threat, choking Chopra out. The Doctor explains it’s the 38th century and 474 is a vat-grown, clone grunt soldier. They hear noises in the corrider. A creature comes at them. They find a room and try to close the door, but the creature gets an arm in. Eventually the creature dissipates in granules.
Deep-Ando is stuck out in the corridor. Nagata tries to contact him, but with no success. The Doctor examines the granules. Clara finds pods that Chopra calls Morpheus. One of them opens and Clara winds up inside. After a moment, it opens back up. 474 says the last Morpheus pod is not empty. They find Rassmussen inside.
A Morpheus hologram explains that they live in a time of prosperity, but they always need sleep. The Morpheus containment unit concentrates the sleep experience into a 5 minute process that provides the chemical benefits of sleep so that you can continue working. Everyone on Triton is using it. They debate the morality of Morpheus. The Doctor says in creating it Rassmussen has also created a monster.
The Doctor says the monster is made of “sleep dust,” the mucus that builds up in our eyes. He says the crew has already been digested. Rassmussen only survived because he hid.
Deep-Ando tries to enter a room, but the computer demands he “do the song.” Apparently the computer was reprogrammed by the crew after a Christmas party. He has to sing “Mr. Sandman,” the Morpheus song. The creatures nearly reach him before the door finally opens.
Rassmussen says Deep-Ando was the first to die.
The gravity shields begin to fail. The Doctor tries to fix the problem. The monsters find them struggling. The Dctor fixes the shield and they run into the galley cold storage. 474 and Chopra are trapped outside.
474 and Chopra are in the halls. They’re trying to find Deep-Ando, but Chopra decides to head for the rescue boat. If the rest aren’t back soon, he’ll assume they’re dead and blow up the station.
The Doctor hacks into their helmet cameras and tries to figure out what they’re missing about the creatures. Nagata points out that they don’t have helmet cams, even though they’re still seeing footage. The Doctor decides to let the Sandmen in.
Chopra and 474 are stuck in the hall because of the damage. They’re surrounded by Sandmen. 474 says he can save them and knocks Chopra out.
The Doctor figures out that the creatures can’t see, so he lets them into the cold storage. He, Nagata and Clara sneak out and lock the Sandmen in.
Chopra wakes up to 474 dying, but they’re on the other side of the wreckage. 474 sends Chopra off while he fights the Sandmen.
The Doctor shows some footage and asks what’s wrong with it, what’s missing. The problem is there are no cameras. So how and why does the footage exist? It’s being recorded using the Sandmen, but by who and why? He says it’s the Morpheus process. He points out that there’s nothing from Chopra’s point of view because he refuses to use Morpheus. The Doctor realizes the gravity shield didn’t fail, it was powered down. He realizes that something was being kept alive.
Chopra continues t make his way through the station. He enters a room and screams as the door closes behind him.
The Doctor and company goes back to the rescue ship and finds Rassmussen there. Rassmussen says the Sandmen can’t be fought. They made him see that humans are simply their food, but that’s the way it is. He agreed to help them if they spared him. He’s got a container with “patient zero,” a man who hasn’t slept in 5 years. Nagata pulls a gun, and Rassmussen opes the container, letting Patient Zero out. The Doctor distracts Patient Zero and Clara and Nagata run out. Nagata shoots Rassmussen. The Doctor ssays things aren’t making sense, it’s like things are being done just for effect.
They try to make it to the TARDIS, but they’re surrounded by Sandmen. The Doctor self-destructs the gravity shields. The escapes into the TARDIS.
Rassmussen is on screen again. He says the message isn’t an alibi, it’s his plan. The message contains the Morpheus signal, Rassmussen is revealed as a Sandman.