Dear TVZ listeners and readers, we have our first flawless Who of the season. Unsurprisingly, it comes to us from writer Steven Moffat. He’s given us Captain Jack and Sally Sparrow. He’s had the Doctor battle clockwork androids and bump into his fifth incarnation. He’s got a lot to live up to.

The episode begins in a normal, apparently present-day suburbian home where a little girl is talking with her therapist, Dr. Moon (played by Colin Salmon of the Pierce Brosnan-Bond era and Resident Evil fame). She reveals that when she closes her eyes she goes to her Library, a whole planet of books. The CG here is some of Who’s strongest, reminding a viewer of a utopian, peaceful version of Star Wars’ Coruscant or Bespin. Very pretty.

The little girl enters one library room, alone and quiet. Suddenly there’s banging on a closed door. “Someone’s trying to enter my library,” she tells Dr. Moon, her eyes still shut. The door bursts open and Donna and the Doctor burst in and lock the door, only to turn around and apologize for barging in. The little girl snaps her eyes open, shocked. Huh? They entered her mind? We’ll start piecing this one together throughout, so pay attention!

Opening credits.

The Doctor and Donna arrive in the Tardis in the library and they step out into a massive lobby. The Doctor explains that this is called The Library, a world that is home to every book ever written, powered by the most powerful computer ever. It’s so big that it doesn’t even have a name. It’s just The Library.

Donna wants to know why they’re there. The Doctor reveals someone sent him a note via his psychic paper to come there and help. They find that The Library is totally deserted, however. The Doctor accesses a terminal and it says that the planet has over a million million life forms present on the planet, but only 2 human signatures (theirs).

They walk over to a Node, a sculpture with a human face designed to help visitors. Donna is creeped out by the face, and the Doctor later explains that it’s the 51^st Century and folks like to donate their faces to Nodes when they die. Future culture is silly. The Node warns them about the shadows. Then the lights start to go out in stacks, approaching the Doctor and Donna.

They run for it and get stuck at a wooden door, which the sonic screwdriver can’t work on. So Donna kicks it in, and they lock themselves in a well-lit room (thanks to a glass ceiling letting in the sunlight). They turn around and apologize for barging in, just like we saw at the beginning of the show. But from the Doctor and Donna’s point of view, they see an orb-like machine hovering and when they address it, it drops, inactive. The computer system is marked “CAL.”

At this point a team of astronauts burst into the room. The team is made up of 6 people, lead by Professor River Song (played by ER’s Alex Kingston) who confidently introduces herself as an archaeologist, to the Doctor’s chagrin. The team has been hired by Mr. Lux, one of the astronauts. His family built The Library, but its been silent, sealed for 100 years. He wants to know why. When his assistant, the pretty but not-bright Miss Evangelista asks the Doctor and Donna to sign release forms, they tear them up. They have more important things to do. Oh, and Professor Song reveals she was the one who called the Doctor to come help.

River pulls out a battered journal and asks the Doctor if he’s done certain things, going further and further back in her journal, until she takes a close look at him and realizes that he really doesn’t know her yet. When he asks why he should trust her, she shows that she has his sonic screwdriver, improved over his current version. The Doctor doesn’t know his relation to her yet, but understands that he probably trusts her in the future.

The Doctor explains what’s going on, or at least the current threat. An alien species, called the Vashta Nerada, is actually microscopic and they cluster in swarms in the dark and in the shadows. They’re very, very old and have spread to many planets but they exist in very small numbers and aren’t a threat in general. They hatch from forests in spores, and stay in forests, usually living off of small animals or even dead ones. However, this planet has a severe infestation and while they don’t exist in every shadow, they can exist in ANY shadow. The doctor demonstrates their danger by tossing a chicken leg in a shadow his sonic screwdriver has identified as dangerous and it’s turned into a bone in less than a second.

The astronauts establish themselves in the middle of the room and begin setting up lights. Everyone disrespects Miss Evangelista except for Donna who befriends her. River talks to Donna and is amazed to meet Donna Noble, but when Donna asks why River talks about her as a former companion what happened to her, River goes silent. A big theme of this episode is avoiding “spoilers” about your future. The Doctor accesses a terminal only to appear on the little girl’s tv and they talk for a moment before the signal breaks down. The terminal is again marked CAL.

Donna realizes Miss Evangelista has wandered off and the team go to retrieve her. Instead they find her skeleton. Her suit, like all the astronauts, has a communicator that acts as a neural relay. When people die, their consciousness is stored in its memory for a brief time until it runs out of power. The team hear Miss Evangelista asking where they are and why everything is dark. She is completely sentient but stuck in a rapidly dying communicator and is shortly gone. They call it “Data Ghosting.”

The team goes back to the central room to regroup only to realize that “pilot” Dave (there are two Daves in the team) has a second shadow. His shadow is infected. The Doctor warns everyone to watch out for the shadow and has Dave put his helmet on, hoping that the sealed spacesuit will protect him. “Hey, who turned out the lights?” Dave asks. At first they assume his visor has gone tinted, but then they realize his second shadow is missing and he keeps repeating the same question: “Hey, who turned out the lights?” Then his empty skull thumps forward against the visor. The team runs from the now-possessed and infected spaceman. River pulls out the “square gun” that Captain Jack used to use and opens a hole for them into a new room. Love that! Captain Jack had left the gun on the TARDIS when he and Rose and the Doctor were teleported onto the game show station. Therefore, in the future River must take it, meaning she is at least a companion of the Doctor, if not more.

The Doctor decides to use The Library’s teleport system to send Donna to the TARDIS while the rest of the team investigates the problem. He sends her away and she begins to materialize in the TARDIS only to scream and fade away. The little girl, in her home, says, “Donna Noble has been saved.”

The team pauses from running at a Node for an update. The Node turns and Donna’s face is on it. She tells the Doctor that Donna Noble has been saved. As the episode ends, the team is running from the Vashta Nerada in Dave’s suit and Dr. Moon tells the little girl that her dreams are the real world and that her life in this house with her father are the illusion!

Man, what an episode! What more could you ask for? It’s got a baffling number of mysteries, a very scary new alien menace, a fascinating new character in River Song, and genuine emotional beats surrounding our protagonist. I cannot wait to see how this one ends.

Easily worthy of five out of five sonic screwdrivers!