Arthur and Seward successively give their blood to restore Lucy after an unseen force drains her toward death.
At Hillingham, Van Helsing performs an emergency transfusion from Arthur Holmwood into the nearly bloodless Lucy Westenra. Arthur's young strength restores color and pulse, but the improvement vanishes after a single night without a watcher.
John Seward then becomes the second donor, giving his blood under his former master's direction. The procedures preserve Lucy temporarily while proving that an enormous quantity of blood disappears without stain or ordinary medical cause.
A sequence of late-Victorian bedside procedures using transfusion apparatus, opened veins, careful monitoring, and exhausted male donors beside Lucy's sickbed.
The transfusions repeatedly rescue Lucy while quantifying the impossible scale of her nightly loss and binding her protectors to her through literal blood.