Theory:

     “Fight the wolf, indeed! Have you forgotten the story of your sister Kalua who was the size of a big deer. She fought the wolf through the night but was killed in the morning.” Abbu Khan narrated Kalua’s story for the fiftieth time.
 
     To all this Chandni had only one thing to say: “I want to go to the hills.”

     Abbu Khan got very annoyed. He thundered, “You are not going anywhere. From today you’ll live in a small hut, and not move about freely in the compound. Ungrateful as you are, you must still be saved from the wolf.” He pushed her into a small hut and shut the door. But he forgot to close the small window at the back. The same night Chandni made that window her passage to freedom.
Explanation:
 
When Abbu heard such a response from Chandni that she would fight back the wolf, he was taken aback. He had no clue why Chandni said that even after knowing what had happened to Kalua. He told her about his deer-sized goat, Kalua, who fought the wolf all night until being killed the next morning. Abbu Khan told about Kalua for the fiftieth time to Chandni.
 
Despite Abbu's warnings about the dangers of going up to the hills and his story of dead goats, she remained firm in her decision. “I want to go to the hills,” was her sole response to Abbu. Abbu was enraged when he heard Chandni's answers.
 
He yelled at Chandni and confined her to a small hut, fearful of allowing her to roam freely around the compound wall. Abbu considered Chandni to be ungrateful as she was showered with love and protected with more care by Abbu. Still, when Chandni wanted to enjoy her freedom, he pointed out that she was ungrateful. Yet, Abbu's love for Chandni made him take initiative in saving her life. Still, he forgot to close the hut's window. Chandni had used the hut's window to escape from Abbu's place. Despite Abbu's pleas and warnings, Chandni made her flee towards the hill.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
IndeedIn reality
2.
AnnoyedFeeling furious or irritated
3.
ThunderTo shout or complain very loudly and angrily
4.
Infuriate To make somebody extremely angry
5.
SoleOnly or single
6.
YellTo shout loudly
7.
Confine (space) Small space and not free to move about
Reference:
 National Council of Educational Research and Training (2007). Chandni – Zakir Husain (pp. 43- 51). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.