Agent Greer was an agent of the Central Intelligence Agency who was secretly a mole working with Chinese spies. She was the main antagonist of Season 9.
Early Years[]
Steve McGarrett met Greer right after he got his trident, but before he started dating Catherine Rollins. They worked together on a mission in Marrakesh and had a sexual relationship. She suggested Steve could work for the CIA as well, so that they could work in the same city and have a real relationship.
Later, when Steve had already met Catherine but was not dating her yet, Greer encountered Catherine and warned her that Steve wouldn't commit to a relationship, but Catherine later tells Steve she didn't believe Greer.
Season 9[]
Greer is introduced in Cocoon when she and a her colleague Agent Miller come to Hawaii to investigate the death of another agent, Tom Hennessy, who was also a friend of Steve’s. She tells Steve that there is a mole inside the CIA, who works with the Chinese, and Five-0 conceives a plan to find them. Steve lets himself get kidnapped and tortured by the Chinese in order to feed false information to the mole, who turns out to be Greer herself.
In The Man Who Fell from the Sky, she appears with Chinese spies trying to hunt down a mole for the CIA. She gets shot by Tani Rey and is taken into custody.
Greer appears again in When the Light Goes Out, the House Is Dark, where she sells out Steve's Seal team to Omar Hassan, the son of a target they took out in Morocco back in 2002. When Steve confronts her about it, she mocks him and tells him that he can't outrun the assassins. During the gun fight in Montana with Joe, Cole, and McGarrett, Greer escapes from prison and hides from the police.
Steve tracks her down in China in Gone on the Road from which There Is No Returning, after he has arrested Omar Hassan. He confronts here and again asks her why she turned on the men and women she has served with, but she tries to shoot Steve and is shot and killed by Catherine.
| Season Nine | ||||||||||||
| Cocoon | The Man Who Fell from the Sky | When the Sea Draws Out the Tidal Wave, the Rocks Where the Cowries Hide Are Exposed | On the Slope of the Cliff, Not One Jutting Rock is Hidden from Sight | Nothing More the Eyes to Search For | Is Borne on the Back; Is Borne in the Arms | The Smoke Seen in the Dream Now Rises | Birds of a Feather... | Truth Comes from the Night | When the Light Goes Out, the House Is Dark | Gone on the Road from which There Is No Returning | A Bruise Inflicted on an Innocent Person Vanishes Quickly | Those Above are Descending |
| Depressed with the Heat of Kealwalua | Made Prisoner by the Reign of the Rain | When Covetousness is Conceived, Sin is Born | Offer Young Yaro Leaves to | He Who Eats 'Ape is Bound to Have His Mouth Itch | The Octopus of the Deep Spews It's Ink | Way of the Gun | Offspring of an Owl | The Teacher, the Pupil - Let it Come Forth | A Stranger Only for a Day | The Hand is at Fault | Endlessly Pours the Rain of Waianae | |