The smallest secret agents in Britain, and the grown-ups who help them.
Zack has round glasses and blond hair, and he notices everything: the tiniest crumb, the smallest footprint, the faintest sound.
The Noticer. He spots the clue everybody else walks past, and his sticky gloves can walk him straight up a wall.
Danny is brave and fast, and he loves gadgets. He is always first to try something new, even when it is set to much too fast.
The Speedster. He zooms about on rocket skates, and every mission game on this site is about helping him.
Ned is the boys' little brother. He toddles along with a pretzel in each hand, and his nose can sniff out a snack from a very long way away.
Snack Radar. His bubblegum parachute floats him down safely, as long as he remembers it is not a snack.
A very posh gentleman with a bowler hat, a curly moustache, a monocle and an umbrella. He used to be terribly scared of pigeons.
Mission Chief. He gives the boys their missions, and he changes the password every week.
Sophie runs the Gadget Lab, three floors under the ground, full of blinking lights and buzzing machines.
Gadget Maker. Rocket skates, sticky gloves and Frosty Specs all come from her lab. Rule number one: never touch the big blue button.
Mrs Crumble makes the best egg sandwiches in London. She turns up wherever she is needed with a tray, and nobody ever knows how she got there.
Team Helper. Nobody at MI5 can do a single thing until they have had one of her sandwiches.
Wild electric-blue hair that crackles, a glittery purple suit and enormous headphones. He took the Golden Note because he wanted every song to be about him.
Old rival, new friend. These days he waits in the queue with everybody else.
A new friend joins with every episode. New episode every week.
A chatty Cockney pigeon and the best messenger in London. Agent Pickering was scared of him at first.
A shy young artist who loves to draw. He paints the tiniest pictures with the biggest care.
A shy inventor who lives in an icy clock tower. Her snow machine got stuck, and London got snow in July.
Britain's grumpiest food critic, with a very long, very empty dinner table.
A little robot on wheels who lives in a lighthouse full of glowing jars. He had never heard a joke.
Pick an episode, listen to the story, then help Danny on the mission in the game.
See the missions