Here's what happened: Lelouch and Suzaku both missed, but Suzaku rushed Lelouch, removed the bomb and captured him.
Then he traded him to the Emperor for membership in the Knights of the Round.
The emperor has his own geass: to rewrite memories. He used it on Lelouch.
Currently, Lelouch is up to his old tricks: using his geass to steal an enemy Knightmare, directing his forces with inside intelligence, and pulling off miracles.
Kallen wants answers though: did Lelouch use his geass on her, or did she follow on her own.
(It was her choice.)