When a basketball star learns of his own childhood abduction, his guilty mother becomes an insidious rival, jeopardizing his shot at championship glory.

Great points, Debbie and Geno. The word "rival" is a bit confusing. When I looked up the definition used as a noun in the dictionary, it says "a person who is competing for the same object or goal as another, or who tries to equal or outdo another; competitor." If you look at a thesaurus, other terms for rival are "opponent," "enemy," "adversary," etc. Whew! Maybe others will have a different take?

As Clipper announcer Ralph Lawler says, "Bingo! Three points for the big man!"

I don't think rival necessarily implies basketball, at least that wasn't my impression. Perhaps "enemy" or "adversary" is better.

Good job, nice work!

Since I came from a sports background, a "rival" to me was someone who was disliked, and posed the biggest threat to a great season or championship trophy. Of course, I don't want there to be any confusion on the part of the reader, so I will so what other descriptions I can come up with. Thank you for the suggestion.