What Really Happened To Diggle's Brother, Andy?

Long before the death of Sarah Lance, there's been another murder mystery that has plagued the series, Arrow. 

Since season one, John Diggle has been seeking to avenge the murder of his younger brother Andy. However, in his quest for answers, Diggle (and by extension, the audience) has only been riddled with more questions.

Here's what is known. While working as a bodyguard, Andy was shot by Deadshot with poison-laced bullets. Both Diggle and Ollie managed to bring Deadshot down and the assassin was later turned over to A.R.G.U.S. When Diggle broke Deadshot out of a Russian prison during the second season, the assassin sharpshooter revealed that Andy (not the client he was protecting) was the target and he was hired by the group, the H.I.V.E.

Who is the H.I.V.E.?

In the D.C. Comics, the organization stands for the Hierarchy of International Vengeance and Extermination. While the group has featured different line-ups of prominent super villains over the years, what's interesting is that in many adaptations (Teen Titans for example), they have an extensive history with Slade Wilson aka Deathstroke. 

It will be interesting to see if that history will exist in the Arrow Universe as well.

Of course this begs the question why would a bodyguard, even one as accomplished as Andy Diggle, be in the crosshairs of a group like the H.I.V.E.? 

Was Andy affiliated with them? If not, what was he involved in? What did he know that deemed him such a threat that needed to be eliminated?

We know the H.I.V.E./Andy Diggle storyline will be revisited when Arrow returns from winter hiatus.

Will more answers simply lead to more questions? One thing is certain at this point:

Stay tuned.