Gnome Wise, Plops' grandfather, is very ill  and  only has a few days to live. The only thing that can save him is the extract from the carbuncle root. This  root can only be found in gnome woodland, where Plop and his friends live.
Gnome Smart, Wiseís servant, writes a letter to Plop, in which he asks him to bring over, as soon as possible,  some of the extract that can save his master!
Plop is very sad when he reads the letter. He's got the extract but it will take him days to bring it to his grandfather who lives very far away. He will never get there in time to save his grandfather.
Gnome Fixit has an excellent idea: they'll build a big hot-air balloon! The gnomes work all night to build the balloon.  In the mean time Plop finds the extract from the carbuncle root. So by morning, they are ready to go.....to fly!!
Just before departure, Gnome Yum-Yum discovers a pick-nick basket full of plop-biscuits (to take on their flight.).  But the bottle with the extract is also in the basket !!
Yum-Yum takes the basket away, not knowing that the extract is in it, and replaces it with another basket!! Result: the wrong basket ends up in the balloon!
Plop, Fixit, Chatty, Dozy and Fair are waiting to take-off in the balloon .  Only Yum-Yum is missing.
Gnome Fair leaves the balloon to find Yum-Yum. While she's away looking for Yum-Yum, the knot in the rope loosens and the balloon takes off, whithout Fair and Yum-Yum.
Yum-Yum and Fair watch the balloon take off. They decide to walk (not realising  they have the basket with the extract) to gnome Wise's toadstool.
The hot-air balloon ends up in a nasty storm. They are about to crash! But Fixit saves the day!
After a while, there Ìs no firewood left: the balloon has to make a forced landing in a part of the woods where gnomes Scratch, Stink and Snot live. They invite Plop and his friends to have dinner with them. On the menu: frog snot!!
In the mean time: Yum-Yum and Fair are totally exhausted from walking and are both getting very hungry. They meet "big people", who are having a pick-nick in the woods. Yum-Yum and Fair get stuck in the pick-nick basket and end up in the caravan....but they escape.
Gnome Wise has only a few hours left to live.  Many questions are left unanswered: has Plop read the letter? Will he arrive in time ?
Plop and his friends arrive just in time.....they are overwhelmed with joy. When Plop opens the basket, they discover that there is something missing: the extract from the carbuncle root. After all they've been through, it looks as if they won't be able to save his grandfather. At that moment, Fair and Yum-Yum arrive, with the basket and the carbuncle extract!! Gnome Wise is saved!