Read the beginning of the story below and complete the story in 600-800 words.
An Unexpected Guest
Riya was terrified when she heard the news on television that an alien spaceship had landed in her city. As a precaution, her father closed all the doors and windows.
Though everyone was asleep, Riya could not sleep a wink. The thought of aliens in her city kept her mind racing. It was almost midnight when she heard the door bell ring.
By now she was really scared. She ran towards the door but her father instructed her to go back to bed. She pretended to go towards her room, but hid behind the sofa and watched her father open the door.
The moment when the door opened, a hew of bright glow penetrated into the room, which made Riya hardly see anything clearly. With few seconds passed, the bright light suddenly died out, and everything turned back to normal as if there were nothing had happened--but her father disappeared, too.
Witnessed everything, though felt scared and horrible, Riya wanted to go out for help, her leggs, however, trumbled and were too feeble to support her thinny but trembling boby.
"What will they do to father, what if they hurt him and what if he will never come back..." thought Riya. And the more questions she asked herself in the heart, more scareness was burdened on her heart--after all, she was only 14 years old and her father was the only family she had, the only one to cherich.
For her father! she thought, so she mustered up her courage and went out to the door, intending to track her father down. Then, Riya strode steadily towards the door, where she found an envelope lay on the floor.
The envelope, though shrouded in the darkness, was easy to be noticed, something must be applied on its surface so as to attract her attention. Riya piecked it up, curiously and a little surprised, because it may serve as an inevitable evidence to solve all her puzzles.
Unwrapped the envelope, she saw a letter folded in it and when she couldn't wait to open the letter, she recognized it's the handwriting of her father's. The words were written in the red color, placed against the white paper, to make the witing easier to recognize.
There her father wrote-
My little kid. I know it must be hard for you to understand, but I have to tell the truth tonight, though I have kept it a secrete for these years and I had no intention to tell you all of these; however, things have all changed and I have no choice but to tell you: I'm the alien for the comets 47."
Having read to the last word of the firt paragragh, Riya was shocked and couldn't believe her eyes!
"How could be!" thought she.
Then, she contined to read the rest.
"15 years ago, I was one of the member of our exploring group to come to the Earth and I, how to say, was equal to your so called 'scientist' of the group and I had a mission to research of human beings. Then, I adopted you in the local hospital when you were only 10 months. To be honest, I had supposed to raise you up to about 2 year-old and to bring you back to our planet as the object of a series of trials of ours.
However, with each day passing, I gradually grew more affection for you because you were so cute--your smile was alawys looks so pure and bright, and you could never be too naughty to let me chase after you to bring you back to bed; you were the cleverest child I've ever seen--you always raised a lot of strange questions which was beyound my knowledge and puzzled me, a scientist of our planet! And you were such a comfort and consolation to me--it is you to make me feel warm for the first time, and since you were born not so physically strong, I had the chance to feel worried for my little girl as a father. Therefore, I was appreciated for everyday you kept me company and I eliminated the idea of making you as our trials' object and even every human beings on Earth."
Riya now came to realize that no wonder his father looked a little bit strange compared with the common people, no wonder his father's skin was not as warm as she was, and no wonder she had no mother, and no wonder... Every puzzlement seem to have been solved.
"I had thought our ordinary days could went on; however, the other day, my companions from the comet transmitted the message to me to recall me back. You know, I was reluctant to obey their order, but I have no power to resist. I have saved money for your future, put in your wardrobe. I will leave you but my heart will forever be by your side.Love, Your father, Ray."
Having read the whole letter, Riya couldn't help her tears dropping down like the cascade--her father was so considerate as usual! Though her father was an unexpected guest from the universe several years ago, he was the greatest father she had; though the days ahead will make herself to depend on her own, Riya knew her greatest father in the world would keep her company.