Keith's Caravan Charade

 is an unmarked quest in Fallout: New Vegas.

Quick walkthrough
Upon offering a helping hand, Captain Parker at Aerotech Office Park asks The Courier to find evidence that Keith is involved in drug dealing and crooked gambling. The note Investigate Keith's gambling and drug operations is added to the Courier's PipBoy. In Aerotech Suite 200, a pack of marked cards can be stolen from a desk (located in the southwest of the building). The dialogue options with Keith include a Barter check of 45 after which some Jet can be bought from him. Further, a Speech check of 60 lets The Courier inquire Keith's "system" at Caravan revealing that he is using marked cards.