The author frequently employs narrative suspense as a literary device. How does he use it in this section? How is the author using foreshadowing here?

WE see pictures of the effects of suspected Marburg virus. Tom and Peter decide not to tell anybody that they sniffed the tubes with the virus. This leaves all sorts of outcomes and chain of events possible. Certainly the graphic pictures of Marburg serve to foreshadow the disastrous fallout from this virus.