1st Idea: Starts in a blood vessel. A bacterium enters the blood via a cut in the skin. The bacteria swims about in the fluids and encounters many B cells. Many of the B cells ignore it, until a matching B cell grabs the bacterium. The B cell begins its process of cloning itself and eventually releasing antibodies. These antibodies seek out the matching bacteria and then stick to it.
2nd Idea: Starts of with the bacterium swimming in the blood. It makes its journey through the veins until it encounters B cells. It swims through the B cells until it is caught by a matching B cell. The bacterium is absorbed by this B cell and the bacteria's antigen now protrudes through the wall of the B cell. After communication from a helper T cell, the B cell activates and clones itself, producing memory B cells and plasma cells. The plasma cells eject the antibodies, which swim through the blood seeking out the matching antigen carrying bacteria. Upon finding them the antibodies stick to the bacteria.
3rd Idea: Starts of with a virus or bacteria seen swimming through the blood. It enters a lymph node where many B cells are. The virus swims through them until it becomes stuck to one that matches the antigens on the body of the virus. The B cell goes through the procedure of consuming the virus and showing its antigen on its surface. The B cell waits for a helper T cell to come along and activate it. Once activated the B cell can now clone itself and produce memory B cells and plasma cells. The plasma cells release their antibodies, witch exit the lymph node and into a vein to seek out the matching virus.
4th Idea: Inside a vein, blood cells are seen rushing past. A bacterium comes along and passes many red and white blood cells. It pases a few B cells that ignore it, until a specific antigen matching B cell grabs it. The B cell consumes it and shows the antigen on its surface. The B cell enters a lymph node where a T cell activates it. Upon activation the B cell produces memory cells and plasma cells. The plasma cells release antibodies which exits the lymph node and into the blood.