The Divide Series by Elizabeth Kay

When Felix's parents take him to "The Divide"--a spot in Costa Rica where the waters that run down to the Pacific and Atlantic oceans separate--Felix finds himself in a bizarre parallel world where mythical creatures and magic are a reality. There, he meets Betony, a tangle child and herbalist who becomes his friend in this strange land... moreWhen Felix's parents take him to "The Divide"--a spot in Costa Rica where the waters that run down to the Pacific and Atlantic oceans separate--Felix finds himself in a bizarre parallel world where mythical creatures and magic are a reality. There, he meets Betony, a tangle child and herbalist who becomes his friend in this strange land. As Felix explores this new world he soon discovers that its mythical beasts and fairy folk think Felix is a legendary creature who uses practical science instead of magic! Will Felix ever find his way back home...and will he want to? less

After his adventures in The Divide, Felix lives quietly at home with his parents. But Snakeweed, the arch villain, is still at large. Having failed to sell bad magic to the real world, he wants to go back home. All he needs to get there is the spell hidden in Felix's notebook. So Snakeweed pays a visit to Felix--and freezes his parents with a horrible curse that begins to spread like a magical disease. Soon the curse is effecting everything--and the Earth itself may be in danger... moreAfter his adventures in The Divide, Felix lives quietly at home with his parents. But Snakeweed, the arch villain, is still at large. Having failed to sell bad magic to the real world, he wants to go back home. All he needs to get there is the spell hidden in Felix's notebook. So Snakeweed pays a visit to Felix--and freezes his parents with a horrible curse that begins to spread like a magical disease. Soon the curse is effecting everything--and the Earth itself may be in danger. Felix must return to The Divide to find the counter-charm that can cure his parents...and save the world! less

Felix is back at school, but things aren't back to normal! Rhino, the class bully, snatches the mysterious Brandee lamp he had kept from his last adventure in BACK TO THE DIVIDE, and next thing you know, a djinn has taken Rhino hostage and is demanding that Felix return him home to the mystical, back-to-front world. But no sooner is the djinn's wish granted than Rhino escapes into the villanous protection of Skullcap, new chief nasty of the Japegrins... moreFelix is back at school, but things aren't back to normal! Rhino, the class bully, snatches the mysterious Brandee lamp he had kept from his last adventure in BACK TO THE DIVIDE, and next thing you know, a djinn has taken Rhino hostage and is demanding that Felix return him home to the mystical, back-to-front world. But no sooner is the djinn's wish granted than Rhino escapes into the villanous protection of Skullcap, new chief nasty of the Japegrins. It's up to Felix and Bettony to once again use their wits to save both worlds from the ultimate explosive threat of mixed-up science and magic. less