Theory:

Mij was out of the box in a flash. He disappeared at high speed down the aircraft. There were squawks and shrieks, and a woman stood up on her seat screaming out, “A rat! A rat!” I caught sight of Mij’s tail disappearing beneath the legs of a portly white- turbaned Indian. Diving for it, I missed, but found my face covered in curry. “Perhaps,” said the air hostess with the most charming smile, “it would be better if you resumed your seat, and I will find the animal and bring it to you.”

Explanation:

 

Mij leaped out of the box as soon as the author opened it and vanished. There was mayhem everywhere, the people were startled, and a woman climbed up onto her chair. He tried to grab Mij after spotting him hiding behind the seat of a man wearing a white turban, but after getting his face smeared with curry, he discovered that Mij had disappeared once more. The flight attendant then offered to help Mij and told him to return to his seat.

 

Meanings of difficult words:

 
Sl. No
Words
Meanings
1
ValleyA low area of land between hills or mountains, typically with a river or stream flowing through it
2
CrestThe top of a mountain or hill
3
RipeHaving arrived at the fitting stage or time for a particular action or purpose
4
DownpourA heavy fall of rain
5
ShowerA brief and usually light fall of rain, hail, sleet, or snow
6
IntimatelyIn a way that involves detailed knowledge
Reference:

National Council of Educational Research and Training (2007). First Flight. Mijbil the Otter - Gavin Maxwell (pp. 102 - 110). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi..