https://screenrant.com/ncis-season-21-finale-alden-parker-lily-mystery-explained/

The tense NCIS season 21 finale introduced a brand new mystery concerning Alden Parker and the unknown identity of a young girl named Lily.

Parker's Lily Mystery Can Do The One Thing That NCIS Couldn't For Gibbs (https://screenrant.com/ncis-season-21-parker-lily-mystery-childhood-family-gibbs-couldnt/)

The NCIS season 21 finale introduces the mystery of Lily and how it connects to Parker, setting up a storyline that the show couldn't do for Gibbs.