They Don't.
In the episode Under Covers Season 3 episode 6 it think, they are undercover married assassins and although they kiss it is acting. Although it is still a mystery what actually happened that night.
The closest they actually got is in episode Reunion season 7 episode 2. Ziva kisses tony on the cheek but it is very romantic and cute
Long live TIVA!
In the episode called 'Driven' (4x11)
It was season 3 but am not sure of which episode.
pneumonic plague
season five, the same season were jenny shepard, director of ncis, dies.
Requiem
yes
In the episode called 'Driven' (4x11)
He doesn't. Tony does, however, contract the pneumonic plague in the 23rd episode of season two.
It was season 3 but am not sure of which episode.
pneumonic plague
3x08 - Under Covers
season five, the same season were jenny shepard, director of ncis, dies.
Requiem
5x01 Bury Your Dead.
Sub rosa. Season 1 episode 7
Boxed In Season 2
Season 1 "Missing" is the episode I think you're refering to.