The Eternity Trap was the fourth serial of series 3 of The Sarah Jane Adventures. It was written by Phil Ford, directed by Alice Troughton and featured Elisabeth Sladen as Sarah Jane Smith, Daniel Anthony as Clyde Langer and Anjli Mohindra as Rani Chandra.
A haunted house, mysterious whispers and secrets in the shadows attract Sarah's attention. When Professor Rivers and the gang investigate an old legend, a monstrous creature appears in the night. The terrifying grasp of Erasmus Darkening reaches out from centuries past. Sarah and the gang discover the secrets of Erasmus Darkening, but are they too late? Ghosts from the past rise up and the quest to find the missing children reaches a climax. It seems that nothing can stop the ancient alchemist's rise to victory.
Professor Rivers tells the story of a haunted manor. She speaks of Lord Marchwood and how he employed Erasmus Darkening. Marchwood thought Erasmus could make gold out of nothing. His two children, Elizabeth and Joseph, spy on Erasmus and they vanish for eternity.
Rivers is telling the story to Sarah, Clyde, Rani and her assistant Toby. Luke is at home as their standby lest something goes wrong. Sarah Jane separates and finds a book on the history of the manor. She turns from the book case where she is reading, and behind her, the books move. Clyde and Rani go outside and find a shed and a fountain. The fountain ceases flowing and wet footprints appear in the shed. They hear a young girl cry. It stops as Clyde pulls a sheet from a mirror. A man's face appears in the mirror. They run back to the manor to find Sarah.
Meanwhile in the control room, the camera in the playroom cuts out. Rivers goes to investigate. Abruptly, the nursery monitor starts to play. Seconds later, Rivers vanishes.
The gang go to investigate and find all the toys have come alive. On the mirror in the room, a message appears: "Get out". Clyde and Rani explore and find a secret passageway leading to Erasmus' lab.
Meanwhile Sarah goes outside. She finds a creature with red eyes in the bushes. It advances on her. Lord Marchwood's ghost manifests and he fights it off. Clyde and Rani find a computer, then turn around to see Erasmus Darkening.
Lord Marchwood arrives with his children to rescue Clyde and Rani. Sarah hears a recording of Professor Rivers saying, "Sarah Jane help me", over and over. Then she sees her. Rivers warns her, "He is coming for you", and disappears. Sarah reunites with Clyde and Rani and they find Lord Marchwood. Sarah believes they are not ghosts. Toby, Sarah, Clyde and Rani discover all the people that have disappeared, except for Professor Rivers who hasn't been absorbed yet. Erasmus arrives and they all disappear.
Erasmus tells them he will come for them all. Sarah and Toby investigate Erasmus' secret chamber while Rani and Clyde distract Erasmus. Toby tells Sarah of a creature who used to come into his room and watch him every night. Rani and Clyde are chased by something into a game room. When all the games start playing by themselves, they run outside and are locked out.
Sarah and Toby find Erasmus' machine. Sarah suspects Erasmus was trying to get home to another galaxy with the machine. The machine malfunctioned and all the people that disappeared were trapped between dimensions. Clyde and Rani run into the pavilion. Sarah and Toby are interrupted by Erasmus. Sarah works out that the machine is giving Erasmus and all the people that disappeared eternal life. She also works out the creature that attacked her earlier came through the machine. Lord Marchwood again rescues Clyde and Rani. Sarah, Clyde, Rani and Toby reunite with Lord Marchwood. Sarah comes up with a plan to stop Erasmus. Erasmus is destroyed and Professor Rivers is returned. Sarah destroys Erasmus' machine with her sonic lipstick. Sarah, Clyde and Rani say goodbye to Professor Rivers and Toby.
Rani declares that this must be the end of the haunted house dealings. Clyde quickly rebuffs her and says that there were never any ghosts in the first place. He asks Sarah if there really are no such things as ghosts. Sarah answers, "That's right.... No.. such.. thing.. as.. ghosts." Her voice slows and becomes hesitant as she peers up at the manor, seeing something peculiar from up above, before slinking into her car. As the trio drive away, Lord Marchwood and his children watch from the window.
- Sarah Jane Smith - Elisabeth Sladen
- Clyde Langer - Daniel Anthony
- Rani Chandra - Anjli Mohindra
- Professor Rivers- Floella Benjamin
- Erasmus Darkening - Donald Sumpter
- Toby Silverman - Adam Gillen
- Lord Marchwood - Callum Blue
- Joseph Marchwood - Rhys Gear
- Elizabeth Marchwood - Amelia Clarkson
- Mr Scriven - Tony Boncza
Created by Russell T Davies
|Executive Producers Russell T Davies, Julie Gardner and Piers Wenger|
|General production staff|
Camera and lighting department
|Make-up and prosthetics
General post-production staff
Special and visual effects
|Not every person who worked on this adventure was credited. The absence of a credit for a position doesn't necessarily mean the job wasn't required. The information above is based solely on observations of the actual end credits of the episodes as broadcast, and does not relay information from IMDB or other sources.|
- Luke Smith was taught to play chess by Haresh Chandra, whom he then beat six times.
- Professor Sir Rupert Silverman is nominated for the Nobel Prize for physics.
- Johanssen Whalley is a painter.
- James Marchwood carries the title Earl of Marchwood.
- Clyde says, "I ain't afraid of no ghost", a phrase which was part of the Ghostbusters' theme tune.
- Clyde compares the castle to Hogwarts from Harry Potter. Clyde also sarcastically says, "It isn't Santa's workshop." He further mentions Tim Burton, Sweeney Todd, Transylvania and Dracula's castle.
- Rani thinks the bell gonging they hear in the manor is like "Quasimodo on a joy ride", a character from The Hunchback of Notre Dame whose job was to ring a tower bell.
- When Clyde walks into a cobweb, Rani chuckles and says that was "very Spider-Man" of him.
- Rani believes the paranormal encounter with Erasmus is scarier than The Sixth Sense.
- Rani and Clyde are herded into a billiards room by Darkening, with a fresh game of snooker set up on the billiards table.
- The manor's library has copies of Thankless Child and The Day Before Sunrise.
- Thankless Child is a book written by Frank Swinnerton.
- The Day Before Sunrise is written by Thomas Wiseman.
- When Rani and Clyde hole up in the manor's tool shed, Clyde says "It's not exactly the Alamo," and Rani hopes not, remembering it got broken into when the battle to defend the Alamo was lost.
- Erasmus uses a transdimensional exalurator.
- The Stone Tape theory is a speculative explanation for ghosts.
- The services of neither Alexander Armstrong nor Tommy Knight were required for this story. Along with TV: Lost in Time, this is one of only two Sarah Jane Adventures stories not to feature Mr Smith.
- This is the only Sarah Jane Adventures story not to feature Sarah's house 13 Bannerman Road.
- Part 1 — 1.1 million
- Part 2 — 0.93 million
- The faceless being that Toby saw as a child was the Trickster.
- Some people believed that Erasmus Darkening may have been a Time Lord. Sarah commented on Darkening's manipulator having TARDIS-like qualities. Clyde made reference to some aliens looking human and used the Doctor as an example. He seemed obsessed with living forever as if he were a Time Lord on his last regeneration. His clothing was suggestive of Time Lord clothing. The counter-argument is that the Doctor has indicated that he "would know" if there were any other Time Lords still in the Universe. Erasmus was, however, trapped between dimensions, which it is hypothesised may have "hidden" him. In The Day of the Doctor however, it was revealed that Gallifrey was not destroyed but moved to a parallel pocket universe so the idea that Darkening might be a Time Lord is still a possibility. The actor who portrayed Darkening, Donald Sumpter later appeared as Rassilon in the television story Hell Bent.
- The Haunted House in the episode was previously used in Series Four of Doctor Who in TV: Forest of the Dead.
- In part one, when the Professor is taken, her scream can be heard, but the cameras she is using have no audio, as she earlier uses her radio to talk.
- Clyde mentions meeting a Gorgon. (TV: Eye of the Gorgon)
- Clyde mentions the Doctor, whose tenth incarnation he recently met. (TV: The Wedding of Sarah Jane Smith)
- Professor Rivers previously appeared. (TV: The Lost Boy, The Day of the Clown)
- Sarah's heavy scepticism about ghosts and afterlife belief tie in with some of her atheist views. (AUDIO: Dreamland) Here, these views are defied, causing her to re-think her beliefs to some extent.
- The Eternity Trap at Shannon Sullivan's A Brief History of Time (Travel)
- The Eternity Trap at The Locations Guide