Little boy runs away as a man is eaten by a dog. Roll credits.
Holmes is Jonesin for his fix. Nicotine. Including a wonderful little impression of L. Skips an escaped luminous rabbit case. Baskerville is a Chemical and Bilogical weapons plant :)
Quote the first: "In your own time. But quite quickly."
Holmes does his usual thing to the (now grown up) kid. Annoys him, then impresses him. And then tries to get high on secondhand smoke. "They are the footprints of a gigantic hound." interests him. He sends Watson off, and goes to investigate bluebell! "The case of the vanishing glow in the dark rabbit!" Maybe.
Dartmoor: Is very pretty.
Boy remembers "Liberty" and "in". Baskerville has a minefield, for no obvious reason. Watson does something useful! Monster tour guy has a racing times, and a plaster cast of a giant paw print; which Holmes gets to see through a bet with Watson. Just going on the tour is too obvious, clearly. Baskerville is a real base with all sorts of security and stuff. Holmes has stolen Dull's card and they wander in. A scientist (fan) helps them get back out.
Quote the second: "Did we just break in to a military base to investigate a rabbit?"
Dartmoor: Is very stormy.
Quote the third: "Question is: Has she been working on soemthing deadlier than a rabbit?" / "To be fair, that is quite a wide field."
The plan is to bring Boy out onto the moor, and wait and see if anything attacks him. Is this a cunning Holmes plan, or as daft as it sounds? His justification for it is the daft one.
Dartmoor: Is very foreboding.
Someone is signalling with a torch. Mobile phones having passed these people by, obviously.
Dartmoor: Fog, Snarling and Classic werewolfy noises.
Holmes quite emphatically didn't see anything; Boy goes all panic. Holmes appears to be in withdrawal. And admits to seeing a gigantic hound. And panics.
Quote the fourth: "Once you have ruled out the impossible, whatever remains, however improbable, must be true." I know it's a classic quote, but, well, it's classic for a reason.
Holmes does his thing on a random couple because; well, he hasn't had many chances this episode. He's not having a breakdown, honest.
Boy gets scared because his garden lights keep coming on. Watson fails utterly at interrogation, forever.
Dartmoor: Is bright and wild.
Holmes... fails to work out which cupboard has the coffee in. And wonders why it's "Hound" not, you know, "Dog".
Quote the fifth: "Funny doesn't suit you; stick to ice."
Lestrade shows up! On 'hoiday'. Watson useful thing gets investigated! The pub was keeping a big dog fed to attract tourists. But it's dead.
Holmes asks Dull for an invite back in to Baskerville. They comply, but pretty much shut down and hide everything.
We're an hour in, and it's lokoing more an more like an episode of Doctor Who. One of the lame ones with lots of cheap attempts to scare you. Like flashing lights and bent bars on a cage. Watson gets all scared.
Holmes decides it's drugs. And meets the glowy bunny lady! They talk science, sorta. Holmes does thinky stuff. It's... crap.
Boy shoots (at) his therapist. Holmes guesses someone's password. You know, the thing he spent all last episode failing to do. Turns out 'hound' is a project to make a drug that drives people insane. They blame scientist bloke. And send Lestrade to try and catch Boy.
Dartmoor: Is dark.
Holmes talks boy down. Just about convinces him that there's no monster dog. Then it turns up, we get to see it too, at last. Glowing red eyes and all. Holmes accosts Scientist, and Lestrade shoots the dog. Boy goes crazy again, attacking Scientist.
We all get closure when scientist runs away and explodes. (Wait for it... yup, he doe sindeed run away, and explode.)
Dartmoor: Is metaphorical, with a dawn of a new day.