A method of providing interactivity over a set of multiple optical storage media (90, 91) is disclosed. A logical unit, such as a playitem of a playlist is provided on a storage medium (90) of the set of optical storage media (90, 91), comprising information about contents stored on at least one other storage medium (91) of said set of optical storage media. Furthermore, a corresponding optical disc reading apparatus, optical storage medium, and a computer-readable medium, are disclosed.