No Deposit No Return

After finding out that their mother is going to be working through another school holiday, two children are shipped to spend the holiday with their Grandfather. On their way to their Grandfather, the children decide to fly to see their mother in Hong Kong instead but they need money for tickets. They accidentally run into two criminals at the airport and end up in a taxi with them. At the criminal's hideout, the children decide to send a ransom note to their Grandfather to fund their flight to Hong Kong and help the criminals pay a debt. Shenanigans ensue and like O. Henry's novel, of "The Ransom of Red Chief" the ransom decreases as time passes.