At Police HQ they've set up an incident room, the walls already starting to be covered in photographs and reports.

Pictures of the missing children. The bus. The Bus driver.

Sheldon looks it over and ponders "This took planning, They had to buy the bus, hide the paper trail, get it overhauled to make sure it wouldn't break down on them. Whoever did this is too meticulous to risk a mechanical failure from a second hand vehicle.

So an enclosed place, in the city probably near a school bus route as a school bus further out would be noticed and remembered more.

Then fit it with a jammer to block the cell phone signals. Something fairly low powered, it doesn't have to cover a wide area. They switched on when they pulled up ahead of this bus, stopping the kids calling for help, also stops the police tracking the children's phones."

"Then they gave the driver a fake medical to get her body weight and calculated how much anaesthetic to use. That's a lead worth chasing up; they may have used a real medical practise to do the tests for them."

Penny looks at the map of the bus route. "Now that's the weak link, it's not going to a face mask, they were just spraying it randomly. Lots of variables that could affect how fast it too effect – her posture, the weather, what she'd eaten today, the air con."

"Agreed, they can't do it exactly but they can calculate it well enough to know when to start following the bus and just wait for the driver to pass out."

Sheldon points to a long stretch of route with no pick-ups. "This stretch."

"She said she was seeing double – she saw the other bus as the drugs were taking hold!"

Sheldon nods.

"So the bus stops, they pull up in front of it. Turn on the cellular jammer, take the ten youngest kids. They must have given the driver something to counter the sedation

"Could be Epinephrine, dangerous if she had a heart condition but they'd have spotted that on the medical they did."

"so they took the youngest ten, put them on the bus and drove off. They'd want to get off the roads fairly fast so it's likely they returned to their hide out and hid the bus. Then may have then transferred the kids to another vehicle."

"Now, we have two new clues. The traces of breadcrumbs scattered about the front of the bus were all from the same source. The same loaf of mass produced bread."

And the Juice box gave us a partial boot print, a large man's boot.

Detective Hoffsteader bursts in. "City hall just received a ransom note!"

He turns on a large screen. It shows gloved hands opening a sheet of folded paper. More breadcrumbs fall out. On the paper is a haphazard collage of letters and words cut from magazines.

WILL YOU NOT SAVE THE INNOCENT TEN?

10 MILLION DOLLARS

ACCOUNT NUMBER

"The original is already in the forensics lab. The account is a corporate account in the Ukraine, we can't get any replies from the Bank. They're trying to match the paper and glue types while others trace down the lettering styles and fonts to try and work out the sources of the letters. The FBI criminologists are coming on a jet now it's confirmed as a kidnapping for ransom"

Sheldon stands still for several seconds, deep in thought.

"No"

"What?"

"No. it's a trick"

"A trick? What do you mean?"

"The note is a trick. It's a distraction. Theatre. Deliberately over dramatic, made for the TV news headlines. It'lll be carefully prepared to be loaded with clues, all of which will lead you on wild goose chases and make you look foolish while time ticks away"

Hoffsteader looks concerned "Forensics are already saying they may have a break, they saw a hair in the glue of one letter…"

"yes. Fake. It's a trick." Sheldon turns "I think our time is best spent on the boot print. The sole of a boot is like a road map, all the chemical traces preserved, showing us traces of where it's been"

Later in the laboratory

Penny is in a white lab coat, pinning results onto a board. She chuckles "Been a while since I've been around a mass spectrometer, but looks like I've still got it"

Sheldon has things separated onto two boards "So, here we have all the gross physical detritus and here the chemical analysis. We remove the known components of the juice drink style product, a sickly mixture of sugars, flavours and water that's barely seen an actual fruit and what do we have left?"

On the first board "Soil – a dry sandy loam. Asphalt and road dust. Neither particularly unique. And Vegetation."

On the other "Two very unusual peaks – Glycerol and Phosgene"

Penny starts, instinctively looking for a respirator. Chemical weapons drill teaches you to always know where your mask is. "Phosgene!? And we were sniffing it?" She pauses, slowing her breathing by effort of will as she remembers her training. "That's an old WW1 chemical weapon, still in some third world countries arsenals. Pretty easy to make from chlorine and carbon dioxide. It Smells like old hay. Takes several hours from exposure to the first sighs of lung damage. Are you feeling ok? No shortness of breath?"

"Don't worry, the amount here is well below the limit to have any effect on us. But it does help us narrow things down." He looks at the map of the city.

"Looking for a secret chemical weapons lab?"

"No, Traces like this often occur when there has been a fire at a factory using organo-chlorides – plastics manufacture, herbicides or dry cleaners. It would break down with contact with water over time, so won't last long outside. So the fumes must have rapidly got indoors, where it was dry.

"The vegetation is grass pollen. A hardy strain known as red fescue. Not usually used on lawns, but popular with greens managers for golf courses."

"So we're looking for a large dry well ventilated building near a road, with access for a school bus, that's near a golf course and a recent plastic factory fire?"

"Yes, too many possibilities. The Glycerol is interesting. What is it?"

Penny studies it, worried "parts of the IR Spec remind me of something… that phosgene trace makes me think chemical weapons." She starts flicking through a field recognition guide of chemical biological weapons.

"Fuck. Castor bean oil. Are the kidnappers making ricin?"

"Too many people have seen Breaking bad, they see Ricin everywhere. This is different. Ricinoleates. Glycerol. Drama. Stealing Children. The Theatrics. The crushed up Bread."

"It was just Breadcrumbs"

Sheldon stops. "A trail of breadcrumbs"

"yes, I said…"

"No, it's deliberate. Like in a fairy tale. Children lost in the deep dark woods leaving a trail of breadcrumbs."

"Like in a fairy tale? What sort of kidnapper likes fairy tales?"

"This one is doing it deliberately. Playing with themes, making it dramatic, news friendly. They want this to make an impression, to be heard the world over." He pales. "This isn't designed to end well. They want us to get to them just too late. To make bigger headlines"

"That's sick"

Sheldon looks at the Glycerol spectra again "Of course! The witches house!"

"what, we're looking for a gingerbread house?"

"No, PGPR! Poly Glycerol Poly Ricinoleate. It's a flow aid used in chocolate manufacture. Made by heating castor bean oil up and adding glycerol and alkalines. We are looking for a warehouse or factory recently owned by a confectionary company!"

Detective Hoffsteader hurries over, looking even more worried. "Another message, more breadcrumbs and this note!"

SUFFER THE LITTLE CHILDREN

HURRY THEY ARE DYING

Sheldon puts up a map of the city on the screen and overlays a map of red spots and circles.

"What are these?"

"recent Mobile phone dead zones. I've been talking to Anonymous, got a contact with the local wardriving hacker community."

"The what?"

"Wardriving is the act of driving round observing the electronic scenery, detecting wireless networks and determining how secure they are."

"How is that a war?"

"I believe the term originated in the film Wargames, where Matthew Broderick's character David Lightman writes a program that phones a list of telephone numbers in sequence, looking for one that answers with a modem. Hackers now the use of the prefix "war" for any act of sequential network checking, either wardialing a sequence of phones, pinging IP addresses or in this case driving round listening out for open networks."

"And that's legal?"

"Indeed it is, though it's the equivalent of driving slowly down a street looking into each house to see left a door or window open. Actually using the information and breaking into someone's systems is when it becomes illegal."

"So they've been driving round measuring signals for fun? What kind of weird nerds…"

Sheldon just looks at her

"your kind, right."

"So, on the map we look for confectionary property in a recent cellular dead zone that is in an industrial area near a recent plastic fire and a golf course."

He stabs his finger at the map

"Addlestone A03 Logistics. Supplied raw materials to the confectionary industry. Company went out of business two years ago. Assets are with receivers. They had a warehouse in Southwest Industrial park, Fontana that was rented out recently. Nearby drycleaners had a fire four months ago. Golf course to the South East. Few blocks from a High school so no one would comment on a school bus. It all fits"

Detective Hoffsteader runs for the door "I'll alert the SWAT Team, lets GO!"

Sirens blaring and lights flashing, a convoy of cars and SWAT vans hurtle across the city.

In the back of Detective Hoffsteader's car Sheldon is bringing up details on the building on his phone.

"The lot is surrounded by a fence, half open space for several trucks to turn or park, the rest a warehouse. Two roller doors on the side for truck access, doors on the front and side, fire doors on the back. Inside should be mostly open ware house space, with two offices to the front and a bathroom and kitchen to the rear.

Hoffsteader is on the radio to the SWAT team "Plan is the first car pulls up by the gate, entry team has bolt cutters and other entry tools. They get the gate open and we drive both vans in. Team one to the side, team two takes the front. The second car goes round back to cover the back exits. We follow up."

"Sounds like a plan" Penny says. "we need to get in there fast, but be careful. WE don't know what we're up against. There could be armed kidnappers or booby traps"

"Let's hope not! My gear bag is on the floor there, you can take my back up gun"

Sheldon shakes his head "I don't need one"

Penny pulls her gun from the small of her back "I brought my own".

"Oh… right"

She smiles to herself as she checks her gun over, a customised EMP4 contour compact automatic. In the confines of the car she just puts the gun in her left armpit to work the slide, chambering a round then asks

"Sheldon, think there will traps?"

"I don't think so. The children are meant to be found, just not this soon. So we may catch them off guard, there may be armed kidnappers. We don't want to make this a hostage situation"

The car mounts the kerb, bumping into the lot as the armoured figures of the SWAT Team rush into the warehouse.

One SWAT officer is waiting for them, he bangs on the roof of the car and gestures to his mouth

"Radio coms are down, be careful. Use voice and visual confirmations. Entry teams say the doors are all welded shut, but we forced the cargo dock roller door "

They go in as the shouts of "Clear" start to echo round the place – Inside the cargo door they find the fake school bus. Sheldon peers in the windows and points to the back of the bus "there is the jammer"

Penny stands on tiptoe and looks in. the back seats had been removed, in their place were several bolted down boxes with blinking lights and a rack of car batteries.

"should we switch it off?"

"Not til the kids are clear, it'd be too easy to boobytrap"

The advance carefully, looking round. The windows are all covered up but the lights are on, showing the warehouse space clear in the middle but both long walls have a line of pallets loaded with boxes. All are plastic wrapped but many have been torn open, spilling brightly coloured contents

Penny advances slowly and checks the nearest "Candy bars."

Sheldon frowns. "ah It's hard to say no to Yoo-Hoo. The name literally beckons…"

From the back of the warehouse a SWAT officer shouts "we found them!"

Once medics had checked over the scared, dirty but overall unharmed children, Detective Hoffsteader comes back, all smiles. He holsters his pistol. "Well, you did it. They're all safe. Now we just need to work out who did this" He gestures round the warehouse. "First I guess we can see who ordered all this food"

Sheldon slowly walks round the pallets of food, reading the labels.

Penny looks at the other side, calling out "Crate of Capri-sun pouches. Wow Grape, Apple and Pacific Cooler, not seen that in a while"

"Lunchables?"

"Cans of Easy Cheese over here, with Ritz crackers"

"Bottles of water"

"Cadbury chocolate bars."

"Oreo cookies. You were right about the witches house, this is a regular house of gingerbread"

At the back of the warehouse the fire exit is blocked off with steel drums.

Penny reads the label and shouts over to Sheldon "I found your PGPR, these drums are full of it!"

Detective Hoffsteader joins her "great, we'll get the forensics teams in to look for fingerprints, they must have handled these a lot"

Sheldon looks round slowly "this isn't over. We're still in danger."

Penny looks round, gun in hand "whats wrong?"

"The message didn't say the children would die, it said they were already dying" He looks at the pallets. All the open wrappers and spilled packets. Everything looked normal, all the boxes sealed and wrappers intact, but still…

"Detective, tell the medics to take the children straight to hospital, they need full toxicology checks!"

"You think they were poisoned?"

"I think ALL this food is poisoned!"

Later , at the Hospital

"Toxicology reports are back, all of the children had dangerously high levels of lead in their bodies. Luckily they'd not metabolised too much, they're getting a course of chelating agents to remove it but another day eating that stuff would have given them fatal lead poisoning"

Sheldon has a sample of each food stuff on the lab bench "All the seals and wrappers were intact, all the products were identical to the off the shelf samples, but each has all of its artificial sweeteners replaced with lead acetate."

"Lead acetate?"

"It's archaic name, Sugar of lead, hints at its appearance - a White crystalline powder with a sweet taste. Historically used to sweeten wine, toxic in large doses. Famously it was rumoured to be the favourite poison of one Lucretia Boria.

"Ok, but what does this have to do with the children?"

"The last pope descended from the Borgia line was Pope Innocent the tenth."

"The Innocent ten? That ransom note. And the second one… about suffer the little children"

"Matthew 19:14 Suffer the little children to come unto me, and forbid them not; for of such is the kingdom of God."

"you don't strike me as the biblical type"

"I once attended a summer vacation bible camp when my personal choice, Stamp Camp, was cancelled due to lack of interest. I didn't really pay much attention until they announced there was a Bible quiz"

"Let me guess, you get super competitive at quizzes?"

He gives a dismissive shrug "occasionally"

"but why the random religious stuff?"

"games within games."