When Sergeant Quick points Litefoot towards a body found in the river, completely drained of blood, Litefoot decided that this is not something his dear friend Jago should be involved in. Instead, the professor turns to his old trusted friend, Mr. Gabriel Sanders. (Hey, it's David Collings!)
Jago soon realises that he's being Locked Out of the Loop, and confronts Litefoot and Quick about their sustained lies. A heated argument ensues, during which Jago realises that Litefoot simply doesn't always trust him. So, while Litefoot and Sanders question a poor, blind match girl name Mags who may have witnessed the murder, Jago shows up in disguise. As a filthy old beggar. Mags (who isn't blind at all, and who's known Jago for years) can barely stifle a giggle. Once Litefoot and Sanders are gone, she tells Jago that she definitely saw the murderer — and it was none other than Sanders himself.
Jago rushes back to Litefoot to warn his friend, accidentally letting slip that Mags was the witness. Sanders, standing right behind Litefoot, is quite pleased to hear it and immediately goes off to kill Mags. Jago feels devastated at the loss of a friend, even moreso when Mags rises up from Litefoot's pathology slab and reveals that she's been turned into one of the living undead. She's defeated by Jago and Quick, and the two rush after Litefoot to prevent him from further harm.
Meanwhile, Sanders drops by the Red Tavern in search of Litefoot, and decides to get a drink from Ellie...
Once Jago catches up with Litefoot, it turns out — of course — that Litefoot knew all along that Sanders was a vampire. He simply kept Jago far away from the case in order to protect his friend. Jago accidentally foils Litefoot's plans, but does have a trump card of his own: the police force as right outside the building. Jago and Litefoot use their tried and trusted method of "setting things on fire" to get rid of Sanders, and congratulate each other on a job well done.
... until they realise that Sanders murdered Ellie.
Tropes:
- Anyone Can Die: Poor Ellie is murdered.
- Break His Heart to Save Him: Litefoot is extremely crass towards Jago in this episode, simply to keep him out of trouble.
- Bugs Herald Evil: A swarm of creepy crawlies—including flies, cockroaches, bugs, millipedes and spiders—gathers around Sanders if he stays too long in one spot. He eventually says it is because they can sense his true nature as bringer of death.
- Continuity Nod: Vampires were long since established to be completely real in Doctor Who, and as such need no mundane explanation.
- Downer Ending: Ellie is dead, and may become one of the undead.
- Flies Equals Evil: A swarm of creepy crawlies—including flies, cockroaches, bugs, millipedes and spiders—gathers around Sanders if he stays too long in one spot. He eventually says it is because they can sense his true nature as bringer of death.
- Kill It with Fire: Jago and Litefoot attempt to destroy Sanders by trapping him inside a burning warehouse, and damn near succeed.
- Master of Disguise: Jago may be a fairly rubbish actor, but he's still fantastic at disguises.
- Obfuscating Disability: Mags. Also Older Than They Look, which she uses to her advantage while begging.
- Running Gag: People complimenting Jago on the extremely authentic smell of his tramp disguise, to Jago's confusion.
- Sliding Scale of Vampire Friendliness: Sanders is way over on the nasty side.
- Shout-Out:
- Much like Sherlock Holmes, Jago has a (rudimentary) beggar network.
- Sanders was named for George Sanders, the voice actor for Shere Khan in Disney's The Jungle Book (1967).
- Vampire Procreation Limit: It is revealed that someone killed by a vampire will not as a vampire themselves if the vampire drains all of the blood from their body. As a result, most vampires are careful to do this. However, if a vampire does leave some blood behind in the body, then the victim will become a vampire.
