Graem was possibly the highest member of the conspiracy to sell nerve gas to Vladimir Bierko's group of terrorists, although his father Phillip was involved as well. The other two main members of the conspiracy were Charles Logan and Christopher Henderson. When David Palmer found out about Logan's involvement in the conspiracy, Graem and Henderson gave the order to kill him, and one of Henderson's men successfully assassinated him.
When it seemed that Logan would be exposed as a corrupt president by a recording of a conversation between him and Henderson, Graem told him to shoot himself to avoid being put on trial. As fate would have it, a member of Homeland Security intervened and destroyed the recording, just barely preventing Logan's suicide.
While trying to stop Bierko's final threat, Henderson made a deal with Jack not just for immunity but to disappear as well to avoid being killed by Graem, who was described as powerful and untouchable. However, after Bierko was killed and his plan foiled, Jack killed Henderson, and Logan was exposed shortly after.
Graem returned in Day 6. Jack questioned him about the Russian general Dmitri Gredenko, who was involved with the terrorist leader Abu Fayed. Graem told him that he hired Darren McCarthy (one of Fayed's associates), who stole the five suitcase nuclear bombs that Fayed now has in his possession. Graem set Jack up and tried to have him killed, pretending that Phillip was about to be killed as well so it would look like he was not involved. However, Jack was able to escape, killing the guards.
Graem returned to his house, to his wife Marilyn and son Josh. Marilyn suspected that he was evil but Josh was unaware. Jack stormed into Graem's house and interrogated him, Rick Burke torturing him with hyoscine-pentothal, and Graem revealed that what he was hiding was that he was most directly responsible for Logan's conspiracy and David Palmer's assassination. Jack was furious and attempted to kill him, but decided not to go through with it. Phillip was sure that Graem would reveal more information about their plan under more interrogation at CTU, so he injected him with an overdose of hyoscine-pentothal, killing him.
- In Season 5, Graem is never mentioned to be Jack's brother. This is not revealed until Season 6.
- Graem plays a similar role to Max from Season 2 as the "guy behind the guy". Both survive their initial season and are killed later on (Max is killed in 24: The Game).
- Many were disappointed by Graem, feeling that the writers of 24 did not know what to do with him.