OK Openings Part One: The Ruy Lopez for the White Side

Hello, Rippers!(The name of my lacking fan base) Today we'll start a blog series called OK Openings, and the first blog being about the Ruy Lopez, for White. 

The Ruy Lopez was named after a famous Spanish priest who invented the opening.

This is a very popular opening in top level; actually, in every level! Even the WONDERFUL @TheRipper101 plays it, and that's saying something. In the above diagram, it's a basic e4 e5 opening. 2. Nf3 attacks the e5 pawn, while 2...Nc6 defends it. There's also Nf6 (The Petroff's Defense) which will be covered in a later blog. Now, 3.Bb5 moves the light-squared bishop to attack the c6 Knight, which is guarding the precious center pawn on e5. Though, if black does 3...a6, that isn't bad. At all. 3..a6 is Named after the famous Paul Morphy, regarded as the best chess player in the 19th century. You might think: what if White  takes c6 and then b or dxc6, then Nxe5 winning a pawn! Well, good job on finding a tactical motif, but c'mon, Morphy wouldn't just sac a center pawn like that( he probably would, but that's not the point). See if you can find the move that screws up White's plans: