The Gideon Trilogy Series by Linda Buckley-Archer

1763. Gideon Seymour, cutpurse and gentleman, hides from the villainous Tar Man. Suddenly the sky peels away like fabric and from the gaping hole fall two curious-looking children. Peter Schock and Kate Dyer have fallen straight from the twenty-first century, thanks to an experiment with an antigravity machine. Before Gideon and the children have a chance to gather their wits, the Tar Man takes off with the machine -- and Kate and Peter's only chance of getting home... more1763. Gideon Seymour, cutpurse and gentleman, hides from the villainous Tar Man. Suddenly the sky peels away like fabric and from the gaping hole fall two curious-looking children. Peter Schock and Kate Dyer have fallen straight from the twenty-first century, thanks to an experiment with an antigravity machine. Before Gideon and the children have a chance to gather their wits, the Tar Man takes off with the machine -- and Kate and Peter's only chance of getting home. Soon Gideon, Kate, and Peter are swept into a journey through eighteenth-century London and form a bond that, they hope, will stand strong in the face of unfathomable treachery. less

What happens when a seventeenth-century bad guy has twenty-first-century technology? An accident with an antigravity machine catapulted Peter Schock and Kate Dyer back to 1763. A bungled rescue attempt leaves Peter stranded in the eighteenth century while a terrifying villain, the Tar Man, takes his place and explodes onto twenty-first-century London... moreWhat happens when a seventeenth-century bad guy has twenty-first-century technology? An accident with an antigravity machine catapulted Peter Schock and Kate Dyer back to 1763. A bungled rescue attempt leaves Peter stranded in the eighteenth century while a terrifying villain, the Tar Man, takes his place and explodes onto twenty-first-century London. Concerned about the potentially catastrophic effects of time travel, the NASA scientists responsible for the situation question whether it is right to rescue Peter. Kate decides to take matters into her own hands, but things don't go as planned. Soon the physical effects of time travel begin to have a disturbing effect on her. Meanwhile, in our century, the Tar Man wreaks havoc in a city whose police force is powerless to stop him.Set against a backdrop of contemporary London and revolutionary France, The Time Thief is the sequel to the acclaimed The Time Travelers. less

The Tar Man's employer, Lord Luxon, steals the time machine and travels to 19th century New York - just in time to sabotage the American War of Independence...