Unhappy is related to Cry. Cry is related to Reaction. 
Bacteria is a different concept from Virus. Virus can cause/lead to Infection. Infection is a type of Incident. Incident is part of Episode. 
Unhappy <--RelatedTo--> Cry <--RelatedTo--> Reaction 
Bacteria <--DistinctFrom--> Virus --Causes--> Infection --IsA--> Incident --PartOf--> Episode 