Series 10–12
At nineteen minutes past one in the morning, a star beside Saturn goes out. Maya is sure Saturn's ring is a solid hoop sliding over it, and the old observatory key can take her there to prove it. But nothing out in the ring is what it looks like from home, and the lantern only holds one night of oil.
Sam and Priya follow a warm stone lamp seventeen thousand years back into an Ice Age river valley, where a lost girl named Tavi needs to find her family before winter. Everyone knows Ice Age people lived in caves. Everyone is wrong.
At ten to two on a frosty January night, the sky over the hill turns red, and Leo wants to see the spot on the Sun that did it. The old observatory key takes the cousins to Mercury, as near the Sun as the lantern's light will go. Leo is sure that close to the Sun everything must be an oven, and on Mercury that certainty sends them running the wrong way.
Sam is sure the pyramids were built by slaves, so when a rope snaps on a Giza ramp and a young hauler is hurt, he knows exactly what to do: get him away from the overseer and his staff. But his grandfather's watch has brought the cousins to help a baker's boy named Ipi, and Sam is about to learn how much he did not know.
Ranger Kip's old compass has never moved, until the morning its needle points through the floor. Zara and Tomás have one day in the Amazon to get a stolen baby sloth back to her mother, and the sun sets at six.
Nurse Petra's capsule can shrink two passengers smaller than a blood cell, and Mr Osei has agreed to carry it while he runs the school's charity race. Nia knows exactly how blood goes round the body. She has the diagram to prove it.
When Lena taps a rock with Dr Ade's old hammer, a window of light opens and shows the moment the rock was made. Now a farmer's field in Mexico is cracking and warm, and Kai is sure he knows which mountain to watch.
A Roman statue has fallen onto a sixteen-hundred-year-old mosaic, no crane can reach it, and the rain is coming. Grandma Rosa has an unfinished machine with a label that says LIFTING WITHOUT POWER. Ollie is sure that one pulley and a hard pull will do it.
A research probe carrying the first living sample from the bottom of the Mariana Trench has failed to come up. Isla and Marco dive eleven kilometres in the Lantern to find it. Isla knows one thing for certain: nothing down there makes light, so any light they see must be the probe.
A pair of winged sandals has gone missing from an old talking map, and the story they belong to is fading. Yuki knows exactly where Hermes lives: on Mount Olympus, with the other gods. It says so in every book.
Rosie hates maths, and she has just turned the dial of a vault that has been sealed for seventy-seven years. Now the history wing of the Halden Puzzle Museum is locked, the storm outside has burst a water main, and the only way out is through rooms of numbers older than writing.
Two photographs of the same creek in Yellowstone, thirty years apart: one bare and brown, one green with willows and ponds. A scientist wants to know why. Ava already knows. It's the wolves. Everybody knows. Five days, a tape measure, and a storm will tell her otherwise.
One line of Nana's bread recipe has been rubbed out. When Lucas and Mei start to make it, the pantry door opens onto a bakery in the shadow of the pyramids, where the oven has fallen in and two hundred workers will want bread by sunset. Lucas knows exactly how to make dough rise faster. He is about to find out what is alive in the jar.
One night in the Louvre, the glass in front of the Mona Lisa fogs up from the inside, and Noor hears it humming. When she and her brother Felix touch it together, they land in Florence in December 1913, two years after the painting was stolen, on the night before it is found. But someone else is in Florence with a perfect copy, and Felix is sure he knows which one is real.
Kai can kick a football faster than a car drives through town. What he can't do is make it bend. With the cup final days away and his free kicks given to someone else, he lets Priya film him in slow motion, and finds out the answer was never power. But on the hottest day of the year, the thing that matters most in the final is happening at the other end of the pitch.
An old brass ticket machine prints a ticket for a journey in 1888: Mannheim to Pforzheim, single. Through the next door, Ollie and Zara find Bertha Benz and her two sons quietly pushing the world's first car out of the yard before dawn, to drive it further than anyone ever has. Ollie is sure the engine is all that matters. A hundred kilometres of hills, a chemist's shop and a dark descent will teach him otherwise.
The moth trap on Coldharbour Common should be full of moths, and it is nearly empty. Eleven-year-old Wren is sure that more flowers will bring them back, and her new stepbrother Ezra will believe nothing without numbers. Then Wren pulls up the wrong plant, and finds out what was living on it.
