White Blood Cell, Red Blood Cell, Macrophage, and the cute little Platelets face a threat unlike anything they've ever dealt with before: COVID-19! But even this threat can be defeated, as long as everyone works together. The uplifting and informative series comes to a close with one last tour of the hardworking body, featuring "left shift" in the blood, retinal degeneration, and a simple bump on the noggin. But, of course, as long as there's a job to do, this team won't quit!

Reads from right to left.