Katherine Jackson's Grandson To Settle Family War

Katherine Jackson's fate and fortune may lie in the hands of one of her grandsons ... TMZ has learned.

Trent Jackson, Michael's cousin, and his attorney Ron Rale want TJ Jackson, Michael's nephew, to sit down with Katherine alone and decide who's the victim and who's the villain in what has become a family war.

TMZ broke the story ... Katherine has filed a legal doc claiming Trent has committed elder abuse against her and fleeced her to boot. But, we've now learned Trent and his lawyer have a plan to put the dispute to bed and, at the same time, cast suspicion on the motive of other Jackson relatives.

Rale's proposing that TJ -- the one person whose family loyalty has never been challenged -- sit down with Katherine to discuss the situation at hand. If at the end of the sit-down TJ believes Trent has done harm to Michael's mom, he'll leave for good and if Katherine wants him to stay, he will.

Trent, we're told, believes TJ's one-on-one with Katherine will not only absolve him of any wrongdoing, in the process he will cast doubt on the motives of other family members ... family members he believes are trying to get him out of the way so they have a clear path to the matriarch's bank account.

Trent and Rale are suspicious of other family members ... especially after a 2012 incident in which Trent and Michael's kids reported Katherine missing, only to learn some of her kids had taken her to Arizona. They essentially called it a kidnapping, saying some family members were trying to brainwash her into challenging Michael's Estate in a money grab.