So let's take a look at the following diagram to basically see how retrovirus actually works. So inside the protein capsite of the retrovirus, we have two single strands of RNA molecules. So retrovirus has two copies of a single stranded RNA molecule. And once that retrovirus infects that whole cell, it injects these two individual RNA molecules into that hostel. Now, because it carries that special enzyme known as reverse transcriptase, this enzyme basically binds onto either of these two viral RNA molecules and it begins to transcribe in the opposite direction to how it normally takes in our own cells. So instead of going from DNA to RNA, this goes from RNA to DNA in reverse.