Above left: Cordell Doemling (dressed in white), Mason Verger's doctor and caretaker, doesn't want to leave Starling alone with Mason when she arrives for her interview of him. When Mason says, "Cordell, I think you can leave us now", Cordell responds, "I, uh, thought I might stay - perhaps I could be useful." Above right: Verger responds to this by saying, "You could be useful by seeing about my lunch", at which point Cordell reluctantly leaves the area.
There is a hidden plot in Hannibal whereby Cordell Doemling is secretly helping Hannibal Lecter with his plan to do away with Verger; this is true in spite of the fact that it appears to be the other way around, that is, that Doemling is helping Verger with his plan to torture and kill Lecter (by having him eaten alive by wild boars). Referring to the above screencaps, one inidication we have that Cordell is deceiving Verger is that he is very hesitant about leaving Verger alone with Starling during Starling's interview of him - it's as if Cordell doesn't want to be out of hearing range of anything that might be said between the two of them, in turn suggesting that it is his task to report to someone (i.e., Lecter) on this.
Top left: A van driven by Cordell and carrying Mason Verger, arrives at the building on the Verger grounds in which some specially-bred boars are being kept, so that Verger can exact his revenge on Lecter. Top right: While Cordell is pushing Verger's wheelchair from the van toward the boar pen, a gunshot goes off, and Verger says, "What was that?!" Cordell has a slightly worried expression on his face, but he doesn't hesitate or say anything, and instead keeps pushing the chair toward the boar pen in which Lecter is supposedly going to be eaten alive. However, as indicated above, Cordell is working for Lecter, and he knows that the actual plan is to get Verger killed here at the pen; and Cordell knows that he himself is to be left unharmed, per his prearranged plan with Hannibal. Above left: Lecter (on left, wearing mask), here having been wheeled into the pen by one of his captors, makes a comment on how bad the man smells, in an attempt to get the man to untie him and start a fight. The plan is for Lecter to obtain a gun at the scene from one of Verger's henchmen, and then shoot Verger when he arrives at the pen, but this part of the plan doesn't work out, as the captor Lecter taunts is somehow able to keep his cool. Above right: The wooden slats forming the walls of the boar enclosure are starting to weaken, and the boars are about to burst into the pen. This happenstance would be unexpected by both parties: Lecter is not expecting the boars to be in the pen at any point, and Verger's own plan is that once Lecter is in the pen alone, with Verger watching from outside it, to let the boars into the pen in a controlled fashion, by opening a gate connecting the enclosure with the pen.
The gunshot Mason heard while being pushed by Cordell in his wheelchair, was due to a gunfight taking place between Clarice Starling (who has arrived on the scene unbeknownst to Cordell and Mason), and Lecter's two captors in the pen, who she eventually overcomes. Due to being shot by a third henchman who had been hiding in the loft above the pen, Starling falls backwards and drops her gun (top left). Hannibal, who has now untied himself (with Starling's help, prior to her being shot), pockets her gun. He then picks her up so that the boars, who have now crashed through the enclosure walls (top right), will not go after her. Lecter hid from Cordell that Clarice was to be a part of his plan here, for otherwise, Cordell would be worried that Starling, not knowing that he is working with Lecter, might try to shoot him. And, of course, Lecter could not tell Clarice ahead of time that Cordell was working with him. The two henchmen who were shot by Starling in the pen, end up being eaten by the boars (above left). Once Cordell and Mason have arrived and are at a location overlooking the pen (above right), Mason sees what's going on, and he tells Cordell to go into the pen and get one of his men's guns, which is lying on the ground, and to go after Lecter. Lecter can't shoot Mason with the gun in his pocket, because he needs both hands to protect Starling from the boars. Cordell refuses to go in the pen out of fear of the boars, and Lecter's suggestion that he throw Mason into the pen, is completely new to him, i.e., it is not part of the prearranged plan.
Above left: After Lecter makes a statement to Cordell implying that he can say Lecter is the one who pushed Mason into the pen, Cordell throws Mason into the pen. Above right: Lecter leaves carrying a wounded Starling.
All of the above is tied in with what was said in part 5, about Lecter being intentionally 'caught' at Union Station - the reason Lecter allows himself to be taken captive there, is so that he can carry out his planned action at the pen (though as described above, things do not go exactly according to plan; Lecter nevertheless gets the upper hand).
