Season 3, Episode 14 - "The Return" - Malcolm puts Oliver and Thea in a dangerous situation that lands them on Lian Yu with Oliver's former enemy Deathstroke. In a flashback, Oliver and Maseo return to Starling City to retrieve the Omega bio weapon.
Season 3, Episode 20″ - "The Fallen" - Ra's al Ghul makes Oliver an offer he can't refuse. The team join Oliver on his journey to Nanda Parbat where a heartbroken Felicity decides to take matters into her own hands.
Season 4, Episode 4 "Beyond Redemption" - Laurel must deal with the repercussions of taking Sara to Nanda Parbat. Meanwhile, Oliver asks Captain Lance for a favor and while he's not surprised at the response, he is surprised at what he finds out next.
Season 4, Episode 5 "Haunted" - When things take a turn for the worse with Sara, Oliver calls in a favor from an old friend who deals in the mystical, John Constantine.
Season 05, Episode 19 - “Dangerous Liaisons”
Oliver, Team Arrow, ARGUS and the SCPD kick off a citywide manhunt for Adrian Chase. Meanwhile, Helix tells Felicity they have a way to find Chase, but they will need something big and illegal from her in return.