Because no Jackson family drama is complete without Papa Joe ... Katherine's estranged husband has finally come to town ... and moments ago, he arrived to the family's famous home in Encino, CA.
It's the first time we've seen Joe Jackson since Katherine was reported missing over the weekend.
Joe -- who spends most of his time in Vegas and rarely comes to L.A. -- pulled up at the Jackson compound roughly 30 minutes ago in a black Mercedes with Nevada plates, wearing his trademark fedora. We're told he checked the mail and disappeared into the home.
Katherine is currently on her way back to L.A.
No word on how long Joe plans to stay in town ... or if he plans to meet up with the family to try to end the drama.