Leaplings, children born on the 29th of February, are very rare. Rarer still are Leaplings with The Gift – the ability to leap through time. Elle Bíbi-Imbelé Ifíè has The Gift, but she’s never used it. Until now. On her twelfth birthday, Elle and her best friend Big Ben travel to the Time Squad Centre in 2048. Elle has received a mysterious warning from the future. Other Leaplings are disappearing in time – and not everyone at the centre can be trusted. Soon Elle’s adventure becomes more than a race through time. It’s a race against time. She must fight to save the world as she knows it – before it ceases to exist . . .

Elle is back! This time she's leaping almost three whole centuries back in time, to catch a thief, help her friend and save our future It's mid-summer's day and thirteen-year-old Elle and her Leapling classmates are visiting the Museum of the Past, the Present and the Future. But on the day of the school trip, disaster strikes, and the most unique and valuable piece in the museum, the Infinity-Glass, is stolen! And worse still, Elle's friend and fellow Infinite, MC² is arrested for the crime! To prove his innocence Elle must leap back centuries in time, to a London very different from today. Along the way she will meet new friends, face dangers unlike any she has ever known, and face an old enemy who is determined to destroy her. Can Elle find the missing Infinity-Glass and return it to its rightful home before it's too late?

Fourteen-year-old Elle and her friends are going to a not-to-be-missed funfair. But a ride on the Ghost Train takes them further than they ever imagined. They end up in 1880, face-to-face with criminal mastermind, The Grandfather! To Elle’s surprise, he needs her help. Someone has threatened to reveal The Gift to the media. If that happens, everyone will know that Leaplings can leap through time; no Leapling will be safe. Meanwhile, Millennia’s power at the head of The Vicious Circle grows. Will Elle work for a villain to save her secret community? Can she and The Infinites crush The Vicious Circle for good?