Jonathan is obviously upset about Mina, and writes in his journal to keep from going crazy.
After going over what happened to Renfield to make sure that everyone was up to speed (and that none of the attendants who worked at the asylum suspected anything), they start discussing Mina's condition.
Mina is going to be kept in the loop again.
She says that if she feels herself getting vampire-y, she'll kill herself. Or ask someone to euthanize her.
Van Helsing says he'd do it, if no one else would, but that she should try to survive until they've killed Dracula, because his power over her will die when he dies.
Their plan now is to go to the house in Piccadilly and sterilize all the boxes of earth there with holy water, and to do the same to the boxes of earth at the Carfax house. That way, Dracula will have nowhere to hide.
The question is, how do they get into the house in Piccadilly?
Nothing easier: do it in broad daylight, with the help of a locksmith. If everyone is well dressed and seems respectable, the police won't interfere.
Arthur Holmwood, as an aristocrat, will arrange for the locksmith. No one will argue with a guy named "Lord Godalming." Quincey Morris will go with him.
Van Helsing, Dr. Seward, and Jonathan will wait while they get the house opened, and then they'll all go in together.
Before they leave, Dr. Van Helsing wants to make sure that Mina is safe.
He's already put garlic, etc up in her room to keep the vampire out, so he wants to bless her, personally, with a Holy Wafer.
But when he puts the wafer to her forehead, it burns her. It actually leaves a mark.
Poor Mina thinks it's a mark of shame because of the contaminating touch of the vampire on her.
Everyone says a prayer together, and then the men set out.
They hit Carfax first because it's closest.
They open each box in turn, and put a little piece of the sacred communion wafer into it, and then screw the lid shut again.
Next, they head into the main part of the city, to Piccadilly. Arthur and Quincey hire someone to let them into the house.
When they go in, they find that one of the boxes is missing.
Dracula must have squirreled it away somewhere else. So he still has one box, somewhere, that he can retreat to.