Looks like a correction is in order, NCIS fans:

We have been operating under the assumption that the upcoming series spin-off would be titled NCIS: Legend. However, it appears as though "Legend" is simply the title of the first NCIS episode on which LL Cool J and Chris O'Donnell appear.

These actors are still expected to lead the eventual spin-off, though a name for that show is yet to be determined.

Got it? Good. Because new details regarding the two episodes that introduce LL Cool J and O'Donnell's characters have been released...

The stars will debut on an installment that airs April 28 and concludes May 5. In the photo below, Mark Harmon's Gibbs is spotted alongside O'Donnell's Special Agent G. Callen.

Here's setup for Callen's appearance: When the discovery of a Marine's corpse grows into a matter of national security, Gibbs' unit must collaborate with the Office of Special Projects.

Joining O'Donnell and LL Cool J within this unit will be: Louise Lombard, Daniela Ruah and Peter Cambor.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.