YOU SAID:
a they told the cat that she had returned a
INTO JAPANESE
彼らは猫に彼女が戻ったと言った
BACK INTO ENGLISH
They told the cat she was back
INTO JAPANESE
彼らは彼女が戻ってきた猫に言った
BACK INTO ENGLISH
They told the cat she returned
INTO JAPANESE
彼らは彼女が戻った猫に言った
BACK INTO ENGLISH
They told the cat she returned
That didn't even make that much sense in English.