Sentence 1: Blair soon finds out that Serena had slept with her boyfriend , Nate Achirawat , the night of her disappearance .
Sentence 2: Serena soon found out that Blair had slept with her boyfriend , Nate Achirawat , the night of her disappearance .
Question: Do Sentence 1 and Sentence 2 express the same meaning? Yes or No?