Ajay, his sister Richa , their Muslim friend Rustom , together decide to spend their holidays from boarding school with their school friend Dipak at his residence at Sivatika in Himachal Pradesh . Rustom was very well off with his father being the head of a former princely state in Uttar Pradesh . Dipak Pant''s father had been on good terms with Ajay and Richa''s parents till his death .Rustom ,Richa and Ajay graciously accepted Mrs.Pant(Dipak''s mother)''s invitation to stay at Sivatika for the holidays . However, Dipak''s delay in fetching them from the station caused great anxiety to the children but their anxiety was increased tenfold when a landslide occured on their way to Dipak''s residence , though it was not monsoon i.e the time for landslides . A warm welcome from Mrs.Pant lightened their spirits besides the scenic beauty of the mountains which extended from the lofty ranges of the Himalayas . Their first introduction to Moti,Dipak''s faithful dog was not a crashing success because Moti did not approve of strangers and his suspicions were aroused when Ahmed (Rustom''s dutiful bodyguard ) used means not approved by Moti to protect Rustom from the dog. The children felt even more scared when someone broke into the house in the dead of the night . They were introduced to many more people including Mr.Das,the owner of a neighbouring farm ,Shivnath - the contractor ,Mr. Hari Lall, his wife - Mrs. Pamela Lall , Motilal - the shopkeeper and Gopi,the gardener . Many buyers were eager to aqquire the sprawling property of the Pants . When Mrs. Pant refused , Dipak was kidnapped . The children set out to find Dipak only to realise that their battle was against a very powerful gang of people who were out to destroy the natural resources of the mountains for their own selfish demands .
Suspicions fell on the Lalls and Mr. Das who were unable to prove themselves innocent . Finnaly Shibu ,the son of the driver was able to locate Dipak but as a result , he himself was held prisoner with Richa . Matters were made worse with the arrival of annonymous notes to Mrs. Pant threatening her to vacate her house or else suffer . A series of accidents including poisened milk made it nearly impossible to stay there , but they did not lose hope . Ajay and Rustom by chance came to know where Richa , Shibu and Dipak were imprisoned . With their wit the children managed to escape and discovered the purpose of the notorious gang and their headquarters , office and storerooms . They were only too late to prevent the gang to set Dipak''s house on fire but luckily everyone managed to escape unscathed because of Mr. Das''s timely action . With the help of the police , they managed to capture the gang leaded by Shivnath the contractor and in details found out thtat the gang was involved in smuggling tree trunks , minerals from the mountains and in such other illegal activities . After making sure that the members of the gang were safely in prison , they were on friendly terms with the Lalls and Mr. Das and resumed their peaceful holidays to enjoy the lush green meadows , covered with thick and green grass , sprinkled lavishly with pale yellow daisies and the patches of forests all around Sivatika . After all , all was well and it ended well .