At the end of season six, Ziva had left the NCIS team in Israel, returning to work as a Mossad officer.
In the first episode of season seven, Ziva is rescued by Gibbs, Tony and McGee and upon her return to Washington, she eventually becomes an NCIS agent after resigning from Mossad for good.
Much of the season's story are then focuses on the Mexican Drug War and Colonel Merton Bell (Robert Patrick), a suspected murderer who hired the lawyer M. Allison Hart to represent him.
Hart quickly becomes a thorn in Gibbs' side by regularly showing up and protecting possible suspects while they are being investigated, claiming that they were her clients.
It also ends in a cliffhanger with Paloma herself traveling to Stillwater and confronting Jackson Gibbs in his shop, leaving his fate unknown.