補足です

Graded Readerは、英語の学習のためにすばらしいシステムと存じます。

私が、原著【も】読むことをお勧めするのは、原著ならではの味わい、作者の文体や癖も含めて、読書の楽しみ、と考えることが理由です。
下記、以前おすすめした、Grishamの出世作、The Firmの、重要な場面です。エリート弁護士が高給高待遇で法律事務所に職を得て、夢のような家を買い、美人の妻と、幸せの絶頂、そこに、同僚弁護士が事故死し、世界がだんだん暗転していく、まさに、変曲点にあたる記述です。

The Firm, John Grisham

【Graded Reader, Penguin Level 5】
They parked behind the Quins' two Mercedes.
Kay met them at the front door. Her eyes were red from crying.
'Oh, Kay, what's the matter?' Abby asked.
'There's . . . there's been a tragedy,' she said.
'Who is it?' Mitch asked.

【原著】
They parked in the driveway behind the new Mercedes and the old Mercedes.
The maid nodded politely, but did not smile. She led them to the living room, and left them. The house was dark and quiet—no children, no voices, no one. They admired the furniture and waited. They mumbled quietly, then grew impatient. Yes, they agreed, they had in fact been invited to dinner on this night, Thursday, June 25, at 6 P.M. Mitch checked his watch again and said something about it being rude. They waited.
From the hallway, Kay emerged and attempted to smile. Her eyes were puffy and glazed, with mascara leaking from the corners. Tears flowed freely down her cheeks, and she held a handkerchief over her mouth. She hugged Abby and sat next to her on the sofa. She bit the handkerchief and cried louder.
Mitch knelt before her. “Kay, what’s happened?”
She bit harder and shook her head. Abby squeezed her knee, and Mitch patted the other one. They watched her fearfully, expecting the worst. Was it Lamar or one of the kids?
“There’s been a tragedy,” she said through the quiet sobbing.
“Who is it?” Mitch asked.

いかがでしょうか。
GRで、筋書きは十分ですね。必要なことは、全部記述されています。こういう本で、とにかくプロットをつかむ、というのは、学習のためでなくても、スピード感があって、面白そうです。

原著では、豪華な友人宅に着いた時に感じる異常な雰囲気と不安を、最初の段落で共有できます（この部分、ＧＲからはすっぱり落ちています）。そして、主人公夫妻の不安、メイドKayの悲しみ、そして、主人公夫妻の人間的なやさしさも、描かれています。
作家としてはあたりまえのテクニックかもしれませんが、こういうところは、Grishamは上手いです。（あと、そこはかとないアイロニーやユーモアも）

GRを読んだ後でもいいので、ぜひ原著を、とお勧めする理由です。ＧＲとは違う楽しみがあるかと。