In London, 1599 some troubadour sings to that chick from Hex. And it looks like he's gonna get some. Or not. Cause Chick from Hex is Lilith, who turs out to be a witch/demon type. Poor girl's getting typecast. The three witches attack Mr. Troubadour and apparently tear him to pieces. Not very hospitable.
The Doctor and Martha arrive in, you guessed it, 16th century London. Martha's worried about fitting in. They go to the Globe Theater. They attend a play and get to see William Shakespeare himself. Will's kinda hot. Imagine that. Lilith is hanging around in the wing with a gris gris or something. Okay, not gris gris--wrong magic system. Will performs crappy standup. Lilith hexes Bill. He promises a sequel to Love's Labours Lost called Love's Labours Won, which is a lost Shakespeare play. The Doctor decides to stick around to see what happened to it.
Will's staying an an inn where Lilith's mum is the innkeeper. He has one more scene to write to finish LLW. The Doctor drops by and Bill is about to throw them out until he sees Martha and goes sproing. The Doctor's psychic paper doesn't work on Will. Lynley, the Master of the Revels demands that Will have his play approved by him before it's performed. He must be the sixteenth century Network Censor, or MPAA. He also uses a dangling participle. He's determined that LLW won't ever be played. Gee, must be something really offensive in there. Too bad we never got to read it.
Lilith grabs something off the Master of Revels--some hair, I think. So he's in trouble now. The witches are determined that LLW be performed tomorrow. Lilith drowns Lynley with a poppet. Martha tries unsuccessfully to revive him. The Doctor recognizes witchcraft was involved in the death.
The witches want Shakespeare to "free" them. Somehow LLW is part of this plan. The Doctor and Martha board in the same bedroom, with a really small bed. Martha focuses on the awkwardness of this while the Doctor remains unaware of it.
Lilith blows green smoke at Will and does some more magic on him so he can write faster. I could use some of that mojo, especially when I'm on deadline. Thanks to the magic, Will finishes the play. Lilith kills the innkeeper and then flies away on her broom.
The Doctor chases down the architect of the Globe Theater, who's currently crazy in Bedlam Hospital, babbling about witches. Shakespeare is a horn dog. Although I think we knew that. He also seems just as interested in the Doctor as in Martha. Hmm. He and Captain Jack should get together.
The actors rehearse the new play. It appears to be some kind of a spell, its power enhanced by the shape of the theater. A spirit is summoned by the rehearsal.
The Doctor, Martha and Will go to Bedlam. They visit Peter, the Globe Theater architect. Lilith views the visit in a scrying bucket with the other two witches. Peter tells them about the witches, then one of them shows up and kills him before he can say anything else. The Doctor makes her disappear by stating her name. She's a Carrionite, planning to end the world. The Carrionite "witches" plan to destroy the doctor. The Carrionites want to take over the Earth. Dude, everybody wants to take over the Earth. Aren't there other planets to take over? The Doctor realizes LLW is a sort of spell composed to concentrate energy in the Globe for the Carrionites' particular purposes. The Doctor heads for All Hallow's St. to find the Carrionites while Will goes to stop the play.
He stops the performance midstream, to the annoyance of the witches, who knock him unconscious with a poppet and continue with the play. The Doctor and Martha find the witches, mostly because the witches want to be found. Well, just Lilith, since the other two witches are at the play. Martha tries to name her, but can't. Lilith is unable to suss out the Doctor's real name to name him. She tries to use Rose's name to rattle him but it doesn't work. She grabs a bit of his hair to use with her doll. It's a DNA replication module, not a poppet per se. Martha revives him. He's down to one heart, though, and Martha starts it back up.
The play continues. The actors speak the last line, which activates the Carrionites' crystal to open the portal for the rest of their people to descend to earth. Carrionites descend on the Globe theater, then fly out into London. The Doctor drags Will out to reverse what's happened, since he's the wordsmith. That's a lot of pressure to put on a writer. Will starts orating with a little help from the Doctor, including JK Rowling references. The Carrionites are sent back where they came from and the world is saved. The three wtiches are trapped in a globe (not the Globe). Will flirts some more with Martha. The play is lost in the maelstrom, which is why I never had to read it in college. Will writes Martha a sonnet (the Dark Lady sonnet).
The Queen shows up to see Will's plays. She greets the Doctor as her sworn enemy and orders him beheaded. The Doctor and Martha hightail it out and escape on the TARDIS.