The actor, who plays Owen on the show, explained that the drama is normally much more focused on relationships.
"I can't tell you much, but it's very dramatic," McKidd told On The Red Carpet. "So it's a big, game-changing, very operatic end to the season."
He continued: "It's pretty intense and kind of action-packed, which is unusual for Grey's because it's kind of a relationship drama. But suddenly it gets kind of fuel-injected - it's a pretty high-octane end to the season."
The season six finale of Grey's Anatomy will air on May 20 on ABC.
> 'Grey's Anatomy' finale details revealed