Complex sentence: Jacq follows Cleo's owner to a clocksmith named Dr. Dupre, but Dupre claims she doesn't know who altered Cleo's protocol-something that is supposed to be impossible to do without destroying the robot's bio-kernel (core).
Split into simpler sentences: Jacq follows Cleo's owner to a clocksmith named Dr. Dupre. She claims not to know who altered Cleo's protocol-something that is supposed to be impossible to do without destroying the bio-kernel (core).