Theory:

     IT was a moonless night in December. A burst of cool breeze from the window was enough to disturb the sleep of Indrani Debi. Half awake she felt for the adjoining pillow, although she knew the answer. Duttada was not there.
    
     “So he has gone to hobnob with that wretched Dibya! At least he might have bothered to close the door.” Even as she muttered her complaints Indrani Debi could not repress her smile. She knew how utterly oblivious her husband was of the practical problems of living. Didn’t his doctor tell him to take special precautions against the cold? But he wouldn’t remember to put on a sweater even if it was lying on his bedside chair! How could he when Dibya had put her spell on him?
Explanation:
 
The story, "The comet I", is about an amateur scientist, Duttada, and his discovery. Duttada was an amateur scientist who lived on the outskirts of Calcutta. His wife was Indrani Debi. The narration starts with a cold December no-moon night. A cold wind awakened Indrani Debi up, and in her half-sleep, she saw the pillow next to her was empty. The answer was self-evident. Duttada, her husband, was not there.
 
Indrani Debi knew where he would be. She assumed Duttada had gone to visit Dibya when he was found to be not there in his room. She felt bad for her husband, who had gone upstairs without even locking the door. She couldn't suppress her smile even as she grumbled about Duttada. She was well aware of her husband's complete lack of awareness of practical problems. She knew her husband's mind was fully occupied with Dibya and his work. She was concerned about her husband, who, despite the doctor's suggestion to protect himself from the cold, didn't bother to put on his sweater, which was lying on his bedside chair. Indrani Debi blamed dibya, believing that she had caused Duttada to become so oblivious to everything around him that he had forgotten to put on his sweater.
 
Duttada's wife.jpg
Duttada's wife in half sleep
  
Meaning of Difficult words:
 
S. No.
Words
Meaning
1.
Adjoining
Refers to something joined or that lies next to
2.
Repress
Trying to control your emotion or feeling without letting it out
3.
Oblivious
Being not aware of things around you
4.
Wretched
Something unpleasant which makes you angry
5.
Muttering
To talk in a low voice to yourself especially when you are embarrassed or complain things 
6.
Precaution
An action taken in order to prevent the harm
7.
Devoid
Lacking or without being something
Reference:
National Council of Educational Research and Training (2008). The Comet - I (pp. 73-80). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.