After Lincoln discovers Ann, he speaks wistfully of her to Jack during nearly their entire proceeding hunt. Jack gets so sick of it that - when they find and dispatch the vampire - he brutally smashes its face in until there's virtually nothing left. When asked what's wrong, he says, "I pretended it was you." Lincoln promptly shuts up.
Although what they find within may be horrific, Jack and Speed's first solo mission is so awfully botched and over the top that you might find yourself chuckling before the whole ordeal is over.
To wit, Abe advises the two to be as inconspicuous as possible, something that they interpret in practice as lurking about McDowell's general area, dressed in black longcoats, and asking everyone within earshot if they knew where McDowell was.
Lincoln's note recounting his experience in the non-battle against the Natives, including how his men lost a lot of blood (to mosquito bites) and similar annoyances.
Henry bouncing around the room like an angry pinball the morning after he saves Lincoln from Bartz. He keeps up a furious diatribe the whole time he's smashing stuff against the floor (and then tiptoeing through it with one shoe on), only pausing to hiss "Thank you" when Lincoln hands him his other boot.
Note that this scene comes immediately after Lincoln perpetrated some Coitus Interruptus between Henry and a random hooker