The TWiPsters solve the case of the Rashy Schoolteacher, and reveal a drug from rotifers that live on the snail intermediate host which paralyzes schistosome cercariae and prevents infection of mice.

The TWiPpers of the bite fantastic solve the case of the Indian Man Who Hiked, and discuss the effects of schistosome soluble egg antigen on infection of lymphocytes with HIV-1.

The TWiPloid organisms solve the case of the Doctor with Chronic Epigastric Pain, and reveal how levels of linoleic acid in the intestine enable the sexual cycle of Toxoplasma gondii in cats.

The metacyclic TWiPomastigotes solve the case of the Child With a Painless Leg Lesion, and reveal how to kill mosquitoes with a genetically modified fungus.

The TWiPlicates solve the case of the Child With Retinal Granuloma, and discuss an association of the complement protein collectin-11 with the pathophysiology of Chagas disease.