Lorna, did you ever watch Quantum Leap? The final episode shows Sam Beckett going into a bar where, like Gibbs, he sits at the bar/counter and watches bits and pieces of his life with some mystical alternatives thrown in. Both shows came from Donald Bellisario's production company. Recycling.

Remember Chip, Abby's unwanted assistant? That's Bellisario's son. And McGee's sister -- Bellisario's daughter. McGee himself is Bellisario's stepson. Another stepson and daughter are NCIS producers, and another son is a producer for NCIS: Los Angeles. Big Daddy takes care of everybody.