Jumping right into the aftermath of last week's humongous cliffhanger, "Three Ghosts" kicks off with Barry Allen working alongside Felicity and Diggle in an attempt to save the life of his hero and mentor. Although Oliver is initially very upset that Barry now knows his secret identity, he quickly comes to terms with the fact that the Central City native could be of some assistance in taking down super-man Cyrus Gold. Here are all of the highlights from this week's episode of "Arrow":

I See Dead People

While initially we're led to believe that Oliver is seeing ghosts from his past due to the rat poison Barry injected into his system, eventually we learn that it's just a terrible case of survivor's guilt effecting his psyche. In other words, he's actually starting to feel bad about the people that he's gotten killed. We've already seen Oliver deciding not to kill people anymore earlier this season, but this is a whole other level of heroism.

Roy Just Wants to Help

After The Vigilante shot an arrow into his leg last week, Roy Harper is still hellbent on finding out the truth about Sin's mysterious dead friend. While tracking down a lead, Roy is taken by Brother Blood and injected with the Mirakuru serum that gave Cyrus Gold his super-strength. Could this mean Roy Harper is now one step closer to becoming the Green Arrow sidekick Arsenal?

Born on a Monday

Upon breaking into Cyrus Gold's apartment, Diggle finds a book about Solomon Grundy. As those of you hardcore DC comic fans know, Cyrus Gold is the name of the gangster who eventually is transformed into Solomon Grundy. Now that Gold has been defeated and has had acid poured all over his face, could he be returning to life as the zombie supervillain from DC comic book lore?

Angry Doctor Ivo

In the flashback portion of this week's episode, Ivo and his men take hold of Oliver, Shado, and Sarah and forces Oliver to choose between the two women. Slade wakes up on the submarine feeling better than new thanks to the Mirakuru serum injected into his system. But with Ivo shooting Shado dead, it's only a matter of time now before Oliver and Slade Wilson become mortal enemies.

Slade's Throwing Shade

Not only did Slade Wilson appear in present day Starling City in the form of one of Oliver Queen's hallucinations, but we also got a glimpse of him sitting at a desk with Brother Blood quivering at his feet. Obviously, Slade's DNA is where Brother Blood has been deriving his version of the Mirakuru serum but to what gain? One thing is for sure though, Slade Wilson really wants to drive an arrow through Oliver Queen's eyeball.

The Flash

At the end of the episode, Barry Allen is struck by a huge lightning bolt, as a result of the S.T.A.R. Labs particle accelerator blowing up across town and thrown headfirst into a shelf full of unstable chemicals. With the quick surge of electricity that pulses through Barry's face, it's quite clear that he is now the scarlet speedster known as the Flash. Next time we see Mr. Allen, here's hoping he's wearing that classic red and yellow costume!